Mikhail Suslov was born in Shakhovskoye, Khvalynsky Uyezd, Saratov Governorate, Russian Empire (now in Pavlovsky District of Ulyanovsk Oblast). His parents were poor peasants; they ran a small peasant farm and didn't even have their own horse. For this reason, his father occasionally sought work as a carpenter (Baku, Arkhangelsk). Soon after the October Revolution, his father quit farm work in the village completely, but his mother, with Mikhail's help, continued to farm until her death in 1920. Subsequently, his father worked as a store-room keeper in a butter factory in the city of Volsk. He became an active member of the Communist Party, but was later expelled from the party because of his drinking, and died in 1930.

At age 16 Suslov joined the Komsomol (Young Communist League) and became an active member of the local organization. In 1918 he worked for the kombed (Poor Peasant Committee) established in his village. Until 1920 he lived in the village of Shakhovskoye and helped his mother on the farm, and sometimes in winter he worked in the village Soviet and on the kombed as the assistant secretary (his father was the chairman of the committee).

In 1919 he began in earnest to be interested in Bolshevist political pamphlets and politics. At the beginning of 1920, he organized a Komsomol branch in his village and became its secretary. He served the party at this time chiefly as a collector in the surplus-appropriation system and as an organizer of aid to poor peasants at the expense of rich peasants (kulaks). He joined the Russian Communist Party (bolsheviks) in March 1921, aged 19.

Between February 1921 and July 1924, Suslov studied at Prechistensky rabfak (Workers' Faculty) in Moscow. After graduating from the rabfak he studied economics at the prestigious Plekhanov Institute of National Economy between 1924-1928. In the summer of 1928, after graduating from the Plekhanov institute, he became a graduate student (research fellow) in economics at the Institute of the Red Professoriat, and taught at Moscow State University and at the Industrial Academy.

In 1931 he abandoned teaching in favour of the party apparatus. He became an inspector on the Central Control Commission of the All-Union Communist Party and on the People's Commissariat of the Workers' and Peasants' Inspectorate. His main task here was to adjudicate on large numbers of ‘personal cases’, breaches of discipline and appeals against expulsion from the party. In 1933 – 1934 Suslov directed a commission charged with purging the party in the Ural and Chernigov provinces. The purge was organized by Lazar Kaganovich who was head of the Central Control Commission in the early 1930s. Suslov's role in the repressive campaigns of 1937 and 1938 is undocumented though it is clear that these campaigns, which wiped out most of the corps of party activists, opened up the way for his rapid advancement.

In 1939 Suslov was appointed as first secretary of the Stavropol Krai, a vital stage in his rise to power within the Party. Suslov attended the 18th Party Congress as representative of the Stavropol Krai. Although he did not speak he was elected to serve on the Central Auditing Commission. Two years later he was elected to the CPSU Central Committee, bypassing candidate membership. War came to the Stavropol Krai in 1942. In the course of their summer offensive German forces took Rostov-on-Don and began a swift advance into the North Caucasus. The retreat was so rapid that in some areas sections of the Red Army were moving east several days before the arrival of the German divisions. The German attack was arrested only in the region of Ordzhonokidze, a day or two's march from the town of Grozny. The German occupation was to last no more than a year, during which the regional party committee saw as its main task the organizing of a guerrilla movement, and Suslov became Chief of Staff of the Stavropol partisan forces.

During World War II, he also supervised the deportations of Chechens and other Muslim minorities from the Caucasus. In 1944 - 1946, he chaired the Central Committee Bureau for Lithuanian Affairs, and anti-Soviet samizdat literature from the height of his power in the 1970s would accuse him of being personally responsible for the deportation and killings of the nationalist Lithuanians who became political opponents of the Soviets in the course of the Soviet re-entry into the Baltic states on their drive to Berlin in 1944.

In 1946 Stalin gave him a seat on the Orgburo and put him to work in the Central Committee apparatus. In 1947 Suslov was transferred to Moscow and at a plenary session he was elected to the Central Committee Secretariat, a body that he would serve on for the rest of his life. The Secretariat then included also Zhdanov, Kuznetsov, Malenkov, Popov and Stalin himself. Suslov enjoyed the full confidence of Stalin and in 1948 he was entrusted with the task of speaking on behalf of the Central Committee to a solemn meeting on the twenty-fourth anniversary of Lenin's death. From September 1949 to 1951 he was editor-in-chief of the central Party daily Pravda. Suslov's first endeavor, from his earliest pronouncements on ideology, was to eliminate all ideological error, in other words to avoid any contradiction of what was laid down in political terms by established directive. In 1949 he was one of the chief organizers of the triumphant celebration of Stalin's seventieth birthday, and in 1964 he performed a similar service for Nikita Khrushchev. In 1976 and 1981 he was the chief organizer of Leonid Brezhnev's seventieth and seventy-fifth birthday celebrations.

In June 1950, he was elected to the Presidium of the Supreme Soviet. Promoted to the Politburo (which was then called Presidium) in 1952 following the 19th Party Congress, he suffered a temporary reversal when Stalin died, as the Presidium reduced the number of its members from 25 to 10, and he was excluded from the new smaller body in 1953. However, he began to recover his authority when he became chairman of the Foreign Affairs Commission of the Supreme Soviet of the Soviet Union in April 1954. In 1955 he was again elected full member of the Presidium, bypassing the customary candidate membership. Suslov played an active part in the events that led to the signing of the Warsaw Pact, traveling to Warsaw in July where he delivered the principal speech at the ceremonies celebrating the revival of People's Republic of Poland. On October 1955 he visited East Berlin for the sixth anniversary of the German Democratic Republic.

In the 20th congress of the communist party in 1956, Khrushchev made his famous Secret Speech about Stalin's cult of personality. In Suslov's ideological report on February 16, he carefully inventoried the principal negative effects of Stalin's cult of personality:

(They) caused considerable harm to both organizational and ideological party work. They belittled the role of the masses and the role of the party, disparaged collective leadership, undermined inner-party democracy, suppressed the activeness of party members, their initiative and enterprise, led to lack of control, irresponsibility, and even arbitrariness in the work of individuals, prevented the development of criticism and self-criticism, and gave rise to one-sided and at times mistaken decisions.

During the Hungarian revolution in 1956, along with Mikoyan, Zhukov and Andropov, he had remained in close proximity with Budapest in order to direct the activities of the Soviet troops and lend assistance to the new Hungarian leadership. In his telegram to Moscow from Budapest on October 24, Suslov and Mikoyan wrote: "We stopped by the corps headquarters for orientation, and from there, in an armed personnel carrier with comrades Ivan Serov and General Malinin, we set off for the city. We were accompanied by tanks, because there was shooting in Budapest at this time and there were casualties on both sides, including Soviet soldiers and officers." Surprisingly, he and Mikoyan did not at first think the Hungarian situation was serious. "We had the impression that Ernő Gerő especially, but the other comrades as well, are exaggerating the strength of the opponent and underestimating their own strength," he wrote.

On November 1956 he delivered the traditional October Revolution anniversary speech in Moscow. Addressing in the newly built Palace of Sports, Suslov conceded the possibility of different roads to socialism, but reminded the audience that there could be no compromise on the question of "defending the gains of the socialist revolution against attempts of former dominating and exploiting classes". The Hungarian Revolution and its aftermath catapulted Suslov to the international stage of news.

In June 1957, Suslov backed Party First Secretary Nikita Khrushchev during his struggle with the "Anti-Party Group" led by Georgy Malenkov, Vyacheslav Molotov, Lazar Kaganovich, and Dmitry Shepilov. The following October he accused Defense Minister Georgy Zhukov of "Bonapartism" at the Central Committee plenum that removed him from all Party and government posts. The removal of the fiercely independent Zhukov had the effect of firmly subordinating the armed forces to Party control.

In a speech on January 22, 1958, Khrushchev officially proposed to dissolve the Machine and Tractor Stations (MTS). This reform had a particular salience on soviet ideology. In a socialist society, cooperative ownership of property was considered a "lower" form of public ownership than state ownership. Khrushchev's proposal to expand the "lower" form of an economic organization whose ultimate elimination was the objective of communist society ran contrary to the Marxist theory as interpreted by Stalin, and Suslov, as the probable editor of Stalin's economic opus, saw Khrushchev's proposal as unacceptable on theoretical grounds. In a Supreme Soviet election speech in March 1958, Suslov avoided recognizing the theoretical significance of Khrushchev's reform, praising the sale of the MTS equipment only as a "practical" measure to increase productivity. Unlike the rest of the Party leaders who participated in the discussion, Suslov also conspicuously refrained from mentioning Khrushchev as the initiator of the MTS reform.

The 21st congress of the party convened in January 1959. Khrushchev wanted to consider the draft of new Seven-Year plan. Countering Khrushchev's assertion that the Soviet Union was moving from socialism to the higher stage of "communist" development, Suslov cautiously demonstrated that Khrushchev's view of "transition from Socialism to Communism" was flawed, and that it didn't have the official stamp of party approval. To belittle Khrushchev's optimistic assertion that the Soviet Union would soon reach full communism Suslov deferred to Marx and Lenin, emphasizing:

Marx and Lenin teach us that communism doesn't appear suddenly, but comes into existence, matures, develops, passes in its development through definite stages or phases... The new period in the development of Soviet society will be marked by the gradual drawing together of two forms of socialist property - state and kolkhoz. ...The process of these social changes will be long, and understandably, cannot end in the course of a seven year period.

This congress brought an icy chill to the already cooling Suslov-Khrushchev relationship. Khrushchev had been trying to reduce Suslov's authority and influence since the Moscow International Communist Conference in November 1957. Suslov, on the other hand, was becoming progressively more critical of Khrushchev's theoretical pronouncements, his political intransigence, and his campaign to eliminate what was left of the old Stalinist guard. There were also deep-seated divergences in foreign and domestic policy between the chief ideologue (Suslov) and the First Secretary (Khrushchev). Suslov was convinced that the United States was the cause of most Soviet domestic and foreign difficulties, and was against Khrushchev's attempts at rapprochement with Yugoslavia. On the domestic arena, Suslov was opposed to Khrushchev's policy of rapid and uncontrolled de-Stalinization and his economic decentralization policy.

On March 14–24, 1959, Suslov toured the United Kingdom as head of a Supreme Soviet delegation. On 25 June that year, he made a trip to France where he addressed the 15th congress of the French Communist Party. On September 27, accompanied by Shelepin and Andropov, Suslov left for Beijing to a summit conference with Mao. At the April 22 Lenin Day meeting, he had even substituted for the absent Khrushchev, opening the ceremony and introducing Otto Kuusinen, who delivered the main speech. On November 1962 he traveled to Bulgaria and made a speech to the VIII congress of the Bulgarian Communist Party.

In October 1964 Khrushchev was ousted. Suslov played a crucial role in this. As in the Anti-Party Group case in 1957, Suslov again assumed the position of senior Party leader, the high priest of Communism and protector of the Party's incorruptibility, this time not as an impartial arbiter, but as an aggressive and ominous prosecutor. Reading a carefully prepared report, Suslov accused Khrushchev of a wide range of serious errors and misdemeanors which, apart from specific issues and policies, narrowed down to condemnation of Khrushchev himself. It is because of this that he is sometimes referred to as the Grey Eminence.

Under Brezhnev, the new general secretary, not only was Suslov's executive authority increased, but his functional responsibilities were also widely expanded. Arvid Pelshe and Yuri Andropov, who became the chairmen of the Party Control Committee and the KGB respectively, owed their careers to Suslov, and it helped him to wield enormous power in the Politburo. Suslov, with his protege Andropov, was also behind the steady rise to power of Mikhail Gorbachev.

During the celebration of the 50th anniversary of the October Revolution in November 1967, Suslov was the host to a large number of foreign Communist delegations, in preparation for an international conference to discuss "the revolutionary revival of the world". The consultative conference took place in Hungary in February 1968, where Suslov delivered a speech calling for rekindling of the "international solidarity among the working class". At the celebration of the 150th anniversary of the birth of Karl Marx in Moscow on May 5, Suslov gave a major speech that touched a broad spectrum of world problems. The lengthy address zeroed in on two new developments affecting the Soviet Union's relations with the rest of the communist world: the growing disarray of the Communist movement itself, and the need for a more revolutionary policy arising out of the political and military consequence of the Vietnam War. Suslov adamantly denied that détente could lead to an eventual reconciliation of the two systems, fearing that the improvement in Soviet-American relations could undermine the basic tenets of international Communism. To Suslov détente meant the avoidance of a military confrontation in an environment of continued conflict and competition for the liberation of the oppressed peoples of the world.

Suslov's aggressive ideology may have played out in more than theory. With his protegé, Yuri Andropov, in place as the new head of the KGB, Suslov apparently instigated a bizarre plot to embroil the USA and Red China in a nuclear war by blaming China for a launch of a Soviet nuclear missile toward Hawaii in early March, 1968. Suslov may have hoped that the Soviet Union would emerge from the resulting nuclear exchange as the world's lone super power and undisputed leader of international socialism. The plot failed when the missile propellant section exploded on launch, sinking the submarine and killing her crew. It is reported that the CIA, using the Glomar Explorer, managed to recover at least part of the sub in 1974.

The 25th Party Congress convened in Moscow on February 24, 1976. In his welcoming speech to the foreign delegates, Suslov recognized the high level of participation, remarking:

There have never been so many fraternal delegations at one of our Party congresses... This is evidence of the further expansion and strengthening of the life-giving bonds of internationalism... The party of Lenin carries high and will continue steadfastly to carry the sacred banner of proletarian internationalism.

During the 1970s he thrust himself into almost every phase of Soviet political life. By the end of the decade, he exercised greater influence than Brezhnev did. He became not only the chief ideologist and senior member of the Politburo and the Secretariat, but an elder statesman and power broker without whose participation and counsel the Soviet gerontocracy became paralyzed and politically unstable after his death. Suslov had complete control over ideology, Agitprop, civilian and military-political education, the media, the State Publishing Committee, Komsomol, inter-party relations and foreign policy. Through Andropov and Pelshe, he had also exercised immense influence on the KGB and the Party Control Committee. He was kept especially busy by the dissident movement which evolved during the 60s and 70s. The system of party education, Znaniye publishing, the preparation of school text-books, the training of party personnel, the relations between the Soviet state and various religions and church organizations were just a few more of the problems which came within the purview of Suslov.

The expansion of Suslov's political influence and functional responsibilities did not curtail the output of his ideological pronouncements. He actually stepped up the level and frequency of his ideological writings and speeches.

At the beginning of the 80s, the political and economic turmoil had seriously eroded the authority of the Polish Communist Party. Suslov's position on this matter carried particular weight as he chaired a special secret commission that was set up in August 1980 to deal with the Polish problem and was unofficially called the "Suslov Commission". Addressing at the congress of the East German Communist Party on April 1981 in East Berlin, Suslov warned Poland, without mentioning it by name, that deviation from the Communist theory would be bad:

Only consistent implementation of Marxist-Leninist principles guarantees the triumph of our socialist ideals... the atmosphere has been poisoned by attempts of reactionary forces to split our community... There is no other road, any deviation from our socialist teachings results in fatal consequences.

Suslov made a second, hurried trip within less than two weeks, this time to Warsaw, Poland. Suslov's threats did not end the crisis, but did contribute to the coalescing of the Polish Communist leadership around Jaruzelski that declared martial law to avoid a possible Soviet intervention.

His death is viewed by some as starting the battle to succeed Brezhnev, in which Yuri Andropov, who secured Suslov's ideology brief, sidelined Andrei Kirilenko and Konstantin Chernenko after Brezhnev's death later in 1982.

Suslov's collected speeches and articles were common in the Soviet Union. The first full publications was of Complete Works edition which was published in 1977 of 100,000 copies had not sold out more than two years after publication even though it was on sale in every street-corner kiosk. Then, in 1980, a little pamphlet appendix of Suslov's collected speeches and articles for the period 1977–80 was published at the give-away price of thirty kopecks and in an edition of fifty thousand copies, ludicrously small for a political pamphlet; it was sold mainly to libraries and party offices. Most of Suslov's works and speeches described the tasks of the Komsomol in the education of young people, the tasks of a people's teacher in bringing the light of knowledge to the masses, the need for careful, seasonal tilling of the soil, the necessity of doing one's very best for the front-line and of fighting bravely when in that position.

Once, the well-known Soviet writer and war diarist, Vasili Grossman, appealed to Khrushchev to have his life's work "Life and Fate", that had been confiscated by the regime, published. Instead Grossman was given an invitation on 23 July 1962 to speak with Mikhail Suslov. At the end of the ensuing conversation Suslov had the temerity to tell the accomplished writer Vasili Grossman that, since "Life and Fate" was more hostile to the ideals of the Russian Revolution than was Pasternak's Doctor Zhivago, "Life and Fate" could not be published for at least 250 years. "Life and Fate" was eventually published in the USSR in 1988 in the time of glasnost.

Suslov wasn't a healthy man. In his youth he suffered from tuberculosis and in later years he became a diabetic. Even as early as 1964, he had to be connected at all times to an intestinal-discharge tube. In June 1976 he suffered a myocardial infarction - a serious heart attack that put him out of commission until mid-September. In 1979, a vitrectomy - a delicate surgical procedure for removing blood from the vitreous fluids of the eye-ball, an operation associated with a common complication of diabetes, was performed on Suslov by Dr. Svyatoslav Fyodorov, a world renowned Soviet ophthalmologist with the help of three American eye surgeons specially invited from the Johns Hopkins University to demonstrate the newest American methods of treating diabetes-related eye diseases.

Just before his death, Suslov, due to Yevgeniy Chazov's persistent demand (who, according to his own evidence, was especially close to Andropov) had been undergoing a prophylactic checkup in the high guarded government medical complex Central Clinical Hospital in Kuntsevo District for a few days. Suslov refused to undergo the checkup for a long time. He and his close relatives didn’t see any reasons for it. But Yevgeniy Chazov, the main Kremlin Doctor, insisted and managed to convince Suslov, saying that it was a formal, though necessary medical act. The checkup which took a few days went very well, and the patient and his family were informed about it. Suslov was expected to turn up to work on the 22nd of January (on this very day that very important meetings with Brezhnev were to take place).

On the evening of the 21st of January Suslov was suddenly given a very high dose of some new strong medicine. Suslov was known for taking medicine very carefully, cutting pills (even harmless ones such as valeriana pills) into small pieces and taking micro dosages of them. But here, in the medical center, he was at the mercy of the doctors and had to obey. In the evening he and his daughter were sitting in front of the TV set. Just at that time a jubilee program devoted to the anniversary of Lenin's death was being transmitted. An hour passed after Suslov took the medicine when his head suddenly began to bend to his shoulder. He had hardly said a short phrase in order to pacify his daughter when he fainted. He didn’t regain consciousness any more. It was said later that blood stopped coming into the brain and he suffered a severe stroke. Formally, it was announced that Suslov was kept in a life support machine for two or three days more for some purpose; actually he stopped living immediately after the stroke, on the day he took the fatal pill. The irony of it was that this day coincided with the date of the death of Lenin whose works Suslov knew almost by heart and whom he honored and worshiped.

Suslov's death was a big event in Soviet history. A four-day period of nationwide mourning was announced. The entire media and propaganda machine were assigned to cover his death and glorify him. The official obituary described him as a "major party theoretician" and as a man with a "vast soul, crystal clear morals, exceptional industry who earned the profound respect of the party and the people" and all the newspapers in the country dedicated their whole edition to Suslov, praising him, and publishing his official biography. His body was placed in an open coffin in House of Trade Unions in Moscow. Inside the hall, mourners shuffled up a marble staircase beneath chandeliers draped in black gauze. On the stage, amid a veritable garden of flowers, a complete symphony orchestra in black tailcoats played classical music. Suslov's embalmed body, dressed in a black suit, white shirt and black-and-red tie, lay in an open coffin banked with carnations, red roses and tulips, facing the long queue of mourners. At the right side of the hall, the seats were reserved for the dead leader's family. Then, on January 29, the day of the funeral, classes in schools and universities were canceled and all roads into Moscow were closed. The ceremony was broadcast on every television channel. Two officers led the funeral parade, carrying a large portrait of him. A sea of red floral wreaths followed, adding a brilliant touch to a procession colored mostly in drab grays and black. Behind them, the coffin rested atop a gun carriage drawn by an olive-green military scout vehicle. As the coffin reached the middle of the Red Square it was taken out of the carriage it was placed on, and with its lid removed, it was placed on a red-draped bier facing the Lenin Mausoleum. A lavish eulogy was delivered by General-Secretary Brezhnev who stood alongside with the politburo members at the top of Lenin's Mausoleum in front of Suslov's open coffin: "Sleep in peace, our dear friend. You lived a great and glorious life, you did much for the party and people, and they will maintain your bright memory." Suslov's coffin was lowered into the ground as foghorns blared, joining with sirens, wheezing factory whistles and rolling gunfire in a mournful cacophony. When the noisy tribute had ended, an eerie silence hung for five minutes over Red Square - and the nation. Suslov was buried next to Stalin at the Kremlin Wall Necropolis.

During his life, he was awarded with decorations/medals: Twice Hero of Socialist Labor, 5 Orders of Lenin, Order of October Revolution, Order of Patriotic War 1st degree.

Suslov lived in 26 Kutuzovsky Prospekt, Moscow, at the same building as Brezhnev and Andropov and also had a Gosdacha in Troitse-Lykovo (Троице-Лыково) in the west Moscow district of Strogino named Sosnovka-1 which stretched over 11.5 hectares on the Moskva River with a private beach. He had a wife, Yelizaveta Alexandrovna who was a dentist. She was a member of the Communist Party since 1928. She served as the director of the Semashko Moscow Dental Institute. She died in September 1972 after a long and grave illness. She was given a ceremonial funeral, including a lying in state at the Central Committee headquarters. They had two children: a son (Revolii, named after "Revolution") was born in 1929 and a daughter (Maya) was born in 1939. Maya is a historian and has lived in Austria since 1990.

Mikhail Suslov liked to read and had a big library. He mostly read the classical books and liked some English literature. While he planted himself a few trees at his dacha, he spent a lot of time listening to the birds singing and, in his later life, spent a lot of time with his grandchildren.