This is a list of prime ministers of Japan by time in office.
Of the 64 past prime ministers, six served more than 5 years while twenty served less than a year.
Itō Hirobumi became the first Japanese prime minister in 1885 and is the only person to have served on four separate occasions.
Shinzo Abe is the longest-serving prime minister with over eight years on two separate occasions, while Prince Naruhiko Higashikuni is the shortest-serving at eight weeks.
Katsura Tarō was the longest-serving prime minister in the Imperial period (1885–1947) and the only person to have served on three separate occasions.