Charilaos Trikoupis (Greek: Χαρίλαος Τρικούπης) (July 11, 1832 (O.S.) – April 1896) was a Greek politician who served as a Prime Minister of Greece seven times from 1875 until 1895.

Born in Nauplion in 1832, with family ties to Messolonghi, he was the son of Spiridon Trikoupis, a politician who was Prime Minister of Greece briefly in 1833, and Ekaterini Mavrokordatos, sister of Alexandros Mavrokordatos, who also served as a Prime Minister.

After studying law and literature in University of Athens and in Paris, where he obtained his doctorate, he was sent to London in 1852 as an attaché of the Greek legation. By 1863, he had risen to be chargé d'affaires, but he aimed rather at a political, not a diplomatic, career. Trikoupis' family had been original supporters of the English Party; that and his reserved nature bestowed on him the nickname "the Englishman."

In 1865, after he had concluded the negotiations for the cession by United Kingdom to Greece of the Ionian Islands, he returned to Athens and in 1865 he was elected to the Hellenic Parliament, and in the following year was made Minister for Foreign Affairs, at the young age of thirty-four.

In 1872 he created his own party, called the Fifth Party (Πέμπτο Κόμμα) on a reformist agenda. On June 29, 1874 (Julian calendar) he published a manifesto in the Athens daily Kairoi entitled "Who's to blame?" (Τις Πταίει;), naming the King as the answer. Specifically, he condemned the king for bypassing public opinion expressed in elections in his selection of Prime Ministers. Trikoupis wrote that the political instability which characterized the public life was due to the privilege of the crown as far as the appointment and ousting of governments was concerned. This privilege may have derived from the Constitution of 1864 but it resulted in the formation of weak minority governments based exclusively on the royal favor. Moreover, it underlined that if "a remedy is not applied", the country will revolt. In order to prevent this the writer suggested the restriction of the royal privileges with the introduction of the principle of the "declared confidence" which, as he supported, would bring about the harmonization of the political life via the formation of a basically two-party parliamentary system: "When it (the kingship) sincerely decides to accept that it invites to power only the majority, there is doubt that in Greece, as elsewhere, this enviable honour will not remain exposed for long. Therefore, it is not the fault of the regime, it is not the fault of the representatives of the Nation, it is not the fault of the Nation, if the Parliament is divided in many parties and has not the majority when demanded… The vice lies elsewhere and it is there that a remedy should be sought".

The article landed him briefly in jail, but also boosted his popularity significantly. A year later, on May 8, 1875 he mustered a parliamentary plurality and King George I reluctantly named him as Prime Minister as the leader of a new Reformist party called the New (or Modernist) Party (Νεωτεριστικόν Κομμα).

Among his first acts was the reform of election law and the establishment of the "dedilomeni principle" (αρχή της δεδηλωμένης), i.e. the "declared [confidence of Parliament]", obliging the king to appoint the leader of the party with a plurality of parliamentary votes as the Prime Minister. The dedilomeni principle may have contributed to Greece quickly becoming a two-party state as smaller parties merged in an effort to form a plurality. Initially observed by convention, the dedilomeni has been incorporated into all subsequent Greek constitutions and ushered Greece into modern parliamentary politics. The opposing party to Trikoupis' Modernist Party was the conservative Nationalist Party led by Alexandros Koumoundouros.

With ever-changing alliances in parliament and fluctuating election results, Greece went through twelve prime ministers in the next six years. Trikoupis headed three of these short-lived governments. The 1875 general election on October 4 was considered the most honest elections held to that date in Greece; Trikoupis lost. His short period in office meant he had no opportunity to begin carrying out the aggressive reform program which he had in mind. His foreign policy was to develop the resources of his country so as to create an army and a fleet, and thus to give Greece the power to acquire a leading place among the nations of Southeastern Europe.

It was not until 1882 that he was able to take measures to this end. On March 15, 1882 he became prime minister for the third time (his second period of office, two years earlier, had lasted only for a few months), and at once set about the task of putting Greek finance upon a firmer basis, and of increasing the prosperity of the country by making roads, railways and harbours. Despite his vision of a progressive nation with modern infrastructure, Greece in the latter part of the 19th century was a poor and backwards country. His government was relatively stable and lasted for more than three years. During that time he was able to push through an aggressive program of reforms. Trikoupis was a strong believer in the need to create an infrastructure to support the economy, and to attract foreign investment. A progressive program of road and railroad construction significantly improved internal communications. The most important of the works he campaigned for was the digging of the Corinth Canal. Another project that Trikoupis envisioned during that period was a bridge to connect the cities of Rion and Antirion across the Gulf of Corinth. The bridge was beyond the technical and financial abilities of the young Kingdom at that time; construction began more than a century later. The bridge, officially named the Charilaos Trikoupis Bridge in his honour, was completed in 2004.

His difficulties, however, were now increased by the large expenditure which had been incurred for military preparations while he had been out of office as the result of the union effected between Bulgaria and Eastern Rumelia. The Greeks had demanded a compensation for this shifting of the balance of power from the Ottoman Empire, and had prepared to enforce their demand by an appeal to arms. The Great Powers, however, interfered, and by blockading the Piraeus compelled Greece to remain quiet. Trikoupis nevertheless, believed that he could raise the value of Greek paper currency to par in a short time, and upon that assumption all his calculations were based. Unfortunately for him and his country, he was not able to materialize his belief.

He was defeated at the 1885 general election, but in the following year he resumed office, and again took up the cause of economic and financial reform.

His sixth turn in office (June 22, 1892 – May 15, 1893) was a dramatic one. The country's treasury had been depleted by overspending and systemic corruption often caused by political campaigns in which parties promised massive spending programs. Trikoupis stood before parliament and made the most famous statement of his career: "Regretfully, we are bankrupt" (Greek: "Δυστυχώς επτωχεύσαμε"). The servicing of foreign loans was suspended, and all non-essential spending was cut.

Trikoupis was again in power from November 11, 1893 until January 24, 1895. It was during that time that the planning for the 1896 Summer Olympics was begun. Trikoupis was skeptical about the games, fearing that the country could not shoulder the cost. He was convinced, eventually, to host them, and made the needed arrangements. This would be his last term in office.

Trikoupis tried to make terms with the creditors of his nation, but he failed in this also. The taxation measures he proposed aroused great hostility, and in January, 1895 he resigned. At the general election, four months later, he and his Modernist Party were defeated and he failed even to be elected in Parliament.

After 1895, in poor health and poor personal finances, he moved to France. In the 17 March 1896 elections, his political friends managed to vote him into Parliament again, but Trikoupis never returned to Greece: he died in Cannes on 30 March 1896. He was buried in Athens.
Trikoupis is considered as one of the greatest modern Greek politicians for his reformist and modernising programs, and for the introduction of the dedilomeni principle. Roads in all major Greek cities, as well as the Rio–Antirrio bridge, have been named after him.