Chernenko was born to a poor family in the village of Bolshaya Tes (now in Novosyolovsky District, Krasnoyarsk Krai). His father, Ustin Demidovich (of Ukrainian origin), worked in copper and gold mines while his mother took care of the farm work.

Chernenko joined the Komsomol (Communist Youth League) in 1929, and became a full member of the Communist Party in 1931. From 1930 to 1933, he served in the Soviet frontier guards on the Soviet - Chinese border. After completing his military service, he returned to Krasnoyarsk as a propagandist. In 1933 he worked in the Propaganda Department of the Novosyolovsky District Party Committee. A few years later he was promoted head of the same department in Uyarsk Raykom. Chernenko then steadily rose through the Party ranks, becoming the Director of the Krasnoyarsk House of Party Enlightenment then in 1939, the Deputy Head of the AgitProp Department of Krasnoyarsk Territorial Committee and finally, in 1941 he was appointed Secretary of the Territorial Party Committee for Propaganda. It was in the 1940s that Chernenko established a close knit relationship with Fyodor Kulakov. In 1945, he acquired a diploma from a party training school in Moscow, and in 1953 he finished a correspondence course for school teachers.

The turning point in Chernenko’s career was his assignment in 1948 to head the Communist Party’s propaganda department in the Moldavian Soviet Socialist Republic. There, he met and won the confidence of Leonid Brezhnev, the first secretary of Moldova from 1950 to 1952 and future leader of the Soviet Union. Chernenko followed Brezhnev in 1956 to fill a similar propaganda post in the CPSU Central Committee in Moscow. In 1960, after Brezhnev was named chairman of the Presidium of the Supreme Soviet (titular head of state of the Soviet Union), Chernenko became his chief of staff.

In 1964 Soviet leader Nikita Khrushchev was deposed, and succeeded by Leonid Brezhnev. During Brezhnev's tenure as Party leader, Chernenko's career continued successfully. He was nominated in 1965 as head of the General Department of the Central Committee, and given the mandate to set the Politburo agenda, and prepare drafts of numerous Central Committee decrees and resolutions. He also monitored telephone and wiretapping devices in various offices of the top Party members. Another one of his jobs was to sign hundreds of Party documents daily, a job he did for the next 20 years. Even after he became General Secretary of the Party, he continued to sign papers referring to the General Department (when he could no longer physically sign documents, a facsimile was used instead).

In 1971 Chernenko was promoted to full membership in the Central Committee: Overseeing Party work over the Letter Bureau, dealing with correspondence. In 1976 he was elected secretary of the Letter Bureau. 1977 he became Candidate, 1978 full member of the Politburo, serving second to the General Secretary in terms of Party hierarchy.

During Brezhnev's final years, Chernenko became fully immersed in ideological Party work: Heading Soviet delegations abroad, accompanying Brezhnev to important meetings and conferences, and was a member of the commission that revised the Soviet Constitution in 1977. In 1979 he took part in the Vienna arms limitation talks.

After Brezhnev's death in November 1982, there was speculation the position of General Secretary would fall to Chernenko, however he was unable to rally enough popular support for his candidacy within the Party, and the posting fell to former KGB chief Yuri Andropov.

Yuri Andropov died in February 1984, after just 15 months in office. Chernenko was then elected to replace Andropov, despite concerns over his own ailing health, and against Andropov's wishes (he stated he wanted Gorbachev to succeed him). Yegor Ligachev writes in his memoirs that Chernenko was elected general secretary without a hitch. At the Central Committee plenary session on 13 February 1984, four days after Andropov's death, the Chairman of the Council of Ministers, literally Premier, and Politburo member Nikolai Tikhonov moved that Chernenko be elected general secretary, and the Committee duly voted him in.

Arkady Volsky, an aide to Andropov and other general secretaries, recounts an episode that occurred after a Politburo meeting on the day following Andropov's demise: As Politburo members filed out of the conference hall, either Andrei Gromyko or (in later accounts) Dmitriy Ustinov is said to have put his arm round Nikolai Tikhonov's shoulders and said: "It's okay, Kostya is an agreeable guy (pokladisty muzhik), one can do business with him...." The Politburo failed to pass the decision for Gorbachev, who was nominally Chernenko's second in command, to run the meetings of the Politburo itself in the absence of Chernenko; the latter due to his declining health, began to miss those meetings with increasing frequency. As Nikolai Ryzhkov describes it in his memoirs, "every Thursday morning he (Mikhail Gorbachev) would sit in his office like a little orphan – I would often be present at this sad procedure – nervously awaiting a telephone call from the sick Chernenko: Would he come to the Politburo himself or would he ask Gorbachev to stand in for him this time again?"

At Andropov's funeral, he could barely read the eulogy. Those present strained to catch the meaning of what he was trying to say in his eulogy. He spoke rapidly, swallowed his words, kept coughing and stopped repeatedly to wipe his lips and forehead. He ascended Lenin's Mausoleum by way of a newly installed escalator and descended with the help of two bodyguards.

Chernenko represented a return to the policies of the late Brezhnev era. Nevertheless, he supported a greater role for the labour unions, and reform in education and propaganda. The one major personnel change that Chernenko made was the firing of the chief of the General Staff, Nikolay Ogarkov, who had advocated less spending on consumer goods in favor of greater expenditures on weapons research and development.

In foreign policy, he negotiated a trade pact with the People's Republic of China. Despite calls for renewed détente, Chernenko did little to prevent the escalation of the Cold War with the United States. For example, in 1984, the Soviet Union prevented a visit to West Germany by East German leader Erich Honecker. However, in the late autumn of 1984, the U.S. and the Soviet Union did agree to resume arms control talks in early 1985. In November 1984 Chernenko met with Britain's Labour Party leader, Neil Kinnock.

Because the U.S. had boycotted the 1980 Summer Olympics held in Moscow, the USSR, while under Chernenko's rule, boycotted the 1984 Summer Olympics in Los Angeles. It caused 14 Eastern Bloc countries and allies, including Cuba (but not Romania) to boycott these Olympics. The USSR announced its intention not to participate on 8 May 1984, citing security concerns and stating, that "chauvinistic sentiments and an anti - Soviet hysteria being whipped up in the United States", but some saw it as revenge for the boycott of the Moscow Games. Among those subscribing to the revenge hypothesis was Peter Ueberroth, who was the chief organizer of the Games, in a press conference after the boycott was announced. Iran was the only country that was absent from both Moscow's and Los Angeles' Olympics. The People's Republic of China competed in Los Angeles' games after boycotting Moscow's. For differing reasons, Iran and Libya also boycotted the 1984 event. The boycott was announced on the same day that the Olympic Torch Relay through the United States began in New York City. The boycott influenced a large number of Olympic events that were normally dominated by the absent countries. Boycotting countries organized another major event in July – August 1984, called the Friendship Games.

In the spring of 1984, Chernenko was hospitalized for over a month, but kept working by sending the Politburo notes and letters. During the summer, his doctors sent him to Kislovodsk for the mineral spas, but on the day of his arrival at the resort Chernenko's health deteriorated, and he contracted pneumonia. Chernenko did not return to the Kremlin until the late autumn of 1984. He awarded Orders to cosmonauts and writers in his office, but was unable to walk through the corridors of his office and was driven in a wheelchair.

By the end of 1984, Chernenko could hardly leave the Central Clinical Hospital, a heavily guarded facility in west Moscow, and the Politburo was affixing a facsimile of his signature to all letters, as Chernenko had done with Andropov's when he was dying. In what was almost universally regarded, even by his opponents, as a cruel act against Chernenko, Politburo member Viktor Grishin dragged the terminally ill Chernenko from his hospital bed to a ballot box to vote in the elections in early 1985.

Emphysema and the associated lung and heart damage worsened significantly for Chernenko in the last three weeks of February 1985. According to the Chief Kremlin physician, Dr. Yevgeny I. Chazov, Chernenko had also developed both chronic hepatitis and cirrhosis. On 10 March at 3:00 pm he fell into a coma, and at 7:20 pm he died as a result of heart failure. He became the third Soviet leader to die in just two years' time, and, upon being informed in the middle of the night of his death, US President Ronald Reagan, who was seven months older than Chernenko and just over three years older than his predecessor Andropov, is reported to have remarked "how am I supposed to get anyplace with the Russians if they keep dying on me?"

He was honored with a state funeral and was buried in the Kremlin necropolis – the last person to be interred there.

The impact of Chernenko — or the lack of it — was evident in the way in which his death was reported in the Soviet press. Soviet newspapers carried stories about Chernenko's death and Gorbachev's selection on the same day. The papers had the same format: page 1 reported the party Central Committee session on 11 March that elected Gorbachev and printed the new leader's biography and a large photograph of him; page 2 announced the demise of Chernenko and printed his obituary.

After the death of a Soviet leader it was customary for his successors to open his safe and look in it. When Gorbachev had Chernenko's safe opened, it was found to contain a small folder of personal papers and several large bundles of money; money was also found in his desk.

Chernenko was awarded the Order of the Red Banner of Labour, 1976, in 1981 and in 1984 he was awarded Hero of the Socialist Labor: on the latter occasion, Minister of Defence Ustinov underlined his rule as an "outstanding political figure, a loyal and unwavering continuer of the cause of the great Lenin"; in 1981 he was awarded with the Bulgarian Order of Georgi Dimitrov and in 1982 he received the Lenin Prize for his "Human Rights in Soviet Society."

His first marriage produced a son, Albert, who would become noted in the Soviet Union as a legal theorist. His second wife, Anna Dmitrevna Lyubimova (b. 1913), who married him in 1944, bore him two daughters, Yelena (who worked at the Institute of Party History) and Vera (who worked at the Soviet Embassy in Washington, DC) in the United States, and a son, Vladimir, who was a Goskino editorialist.

He had a Gosdacha in Troitse - Lykovo named Sosnovka-3 by the Moskva River with a private beach, while Sosnovka-1 was used by Mikhail Suslov.