Plath is a surname. Notable people with the surname include:
Aurelia Plath (1907–1994), mother of Sylvia Plath
John Plath, Australian rugby league footballer
Otto Plath (1885–1940), father of Sylvia Plath and entomologist
Sylvia Plath (1932–1963), American poet, novelist, short story writer, essayist
Sylvia Plath effect
Werner Plath (1918–1945), German swimmer
Wolfgang Plath (1930–1995), German musicologist