Tomiichi Murayama is a Japanese politician who served as Prime Minister of Japan from 1994 to 1996. He led the Japan Socialist Party, and was responsible for changing its name to the Social Democratic Party of Japan in 1996. Upon becoming Prime Minister, he was Japan's first socialist leader in nearly fifty years. He is most remembered today for his speech "On the occasion of the 50th anniversary of the War's end", in which he publicly apologised for Japan's past colonial rule and aggression. Of the ten living former prime ministers of Japan, he is currently the oldest living prime minister, following the death of Yasuhiro Nakasone on 29 November 2019. Murayama is also the only living former Japanese prime minister who was born in the Taishō era.

The Japan Socialist Party was a socialist and progressive political party in Japan that existed from 1945 to 1996. The party was founded as the Social Democratic Party of Japan by members of several proletarian parties that existed before World War II, including the Social Mass Party, the Labour-Farmer Party, and the Japan Labour-Farmer Party. The party represented the Japanese left after the war, and was a major opponent of the right-wing Liberal Democratic Party.