Keizō or Keizo is a masculine Japanese given name which can refer to:
Keizō Obuchi (1937 – 2000), Japanese politician, 84th Prime Minister of Japan
Keizo Imai (born 1950), Japanese football player
Keizo Miura (1904 – 2006) Japanese skier
Keizō Kusakawa, Japanese animation director
Keizō Kanie (born 1944), Japanese actor
Keizō Komura (1896 – 1978), Vice Admiral in the Imperial Japanese Navy
Keizō Kitajima (born 1954), Japanese photographer
Keizo Hino (1929 – 2002), Japanese author
Keizo Suzuki (1927 – 1945), Japanese professional Go player
Keizo Yamada (born 1927), Japanese long-distance runner
Keizo Dohi (1866 – 1931), pseudonym Gakken, Japanese dermatologist and urologist
Keizo Takemi (born 1951), Japanese politician
Keizo Nakanishi, musician who performed All I Wanna Do (Keizo Nakanishi song)
Keizo Fukuda, Japanese musician, member of Hifana