Thomas Cullinan may refer to:
Thomas A. Cullinan (1838–1904), American law enforcement officer Thomas Cullinan (Australian cricketer) (died 1907), Australian cricketer Thomas Cullinan (South African cricketer) (1946–2010), South African cricketer Thomas Cullinan (diamond magnate) (1862–1936), South African diamond magnate Thomas P. Cullinan (1919–1995), American author
See also Cullinan (disambiguation)