Keizo Obuchi (小渕恵三; Obuchi Keizō June 25, 1937–May 14, 2000) was a Japanese politician and the 84th Prime Minister of Japan from July 30, 1998 to April 5, 2000.

He was born in Nakanojo Town, Gunma Prefecture. At the age of 13, he transferred to a private middle school in Tokyo, and lived in the city for the rest of his life. In 1958, he enrolled at Waseda University as an English literature major, in hopes of becoming a writer. When his father died that same year, he decided to follow in the old man's footsteps, so he changed his major to political science and graduated with a bachelor of arts degree in 1962.

He briefly started graduate studies at Waseda, but decided that he would learn much more about the world if he went travelling, so between January and September 1963, he visited thirty-eight countries, completely circumnavigating the globe and taking odd jobs as he went. While in the United States, he met Robert F. Kennedy by walking into the attorney general's office.

That November, inspired by his talk with Kennedy, he ran for the House of Representatives and was elected, making him the youngest legislator in Japanese history at 26 years of age. In 1979, he became the director of the prime minister's office and director of the Okinawa Development Agency , his first cabinet post. He served there for eight years before becoming Chief Cabinet Secretary in 1987. He became famous two years later, upon the death of Emperor Hirohito, when he publicly announced the new era name "Heisei" for the new emperor Akihito.

In 1991, he became secretary general of the LDP, and in 1994 became its vice president. In 1997, Ryutaro Hashimoto appointed Obuchi as Minister of Foreign Affairs, where he shone in negotiations with Russia over Japanese claims in the Kuril Islands, as well as negotiations over the unification of Korea.

In 1998, Obuchi's time came: he became prime minister in the LDP's election. During his term, he was focused on two major issues: signing a peace treaty with Russia, and reviving the Japanese economy. His solution to the latter was to increase public spending, which briefly slowed the recession but ultimately did very little to turn it around. His Russia policy also eluded implementation before his death.

Obuchi suffered a stroke on April 1, 2000 and slipped into a coma at Tokyo's Juntendo University Hospital. He was replaced by Yoshiro Mori on April 5, and died on May 14 at the age of 62.