Sixty-five men have served as prime minister, the first of whom was Itō Hirobumi taking office on 22 December 1885.

The current prime minister is Shigeru Ishiba, who succeeded Fumio Kishida on 1 October 2024, following the 2024 Liberal Democratic Party presidential election.

In Japanese, due to the special nature of the work of the head of government, the prime minister's titles vary depending on context, sometimes demonstrating his/her role.

It described a government based on an elaborate and rational meritocratic bureaucracy, serving, in theory, under the ultimate authority of the emperor; although in practice, real power was often held elsewhere, such as in the hands of the Fujiwara clan, who intermarried with the imperial family in the Heian period, or by the ruling shōgun.

[5] Under this system, the Daijō-daijin (太政大臣, Chancellor of the Realm)[6] was the head of the Daijō-kan (Department of State), the highest organ of Japan's pre-modern Imperial government during the Heian period and until briefly under the Meiji Constitution with the appointment of Sanjō Sanetomi in 1871.

[10] The shortest-serving prime minister to date is Prince Naruhiko Higashikuni, who served for fifty-four days: from 17 August until 9 October 1945.

[11] The nominee is then presented with his or her commission, and formally appointed to office by the emperor at the Tokyo Imperial Palace.

In most other constitutional monarchies, the monarch is at least nominal chief executive, while being bound by convention to act on the advice of the cabinet.

Located near the Diet building, the Office of the Prime Minister of Japan is called the Naikaku Sōri Daijin Kantei (内閣総理大臣官邸).

[27] Until the mid-1930s, the prime minister of Japan was normally granted a hereditary peerage (kazoku) prior to leaving office if he had not already been ennobled.

Titles were usually bestowed in the ranks of count, viscount or baron, depending on the relative accomplishments and status of the prime minister.

The two highest ranks, marquess and prince, were only bestowed upon highly distinguished statesmen, and were not granted to a prime minister after 1928.

Certain eminent prime ministers have been awarded the Order of the Chrysanthemum, typically in the degree of Grand Cordon.

However, honours may be withheld due to misconduct or refusal on the part of the prime minister (for example, Kiichi Miyazawa).