Thomas Dyer (1856–1857) was mayor of Chicago, Illinois.
Thomas Dyer may also refer to:
Thomas Dyer (MP) for Bridgwater (UK Parliament constituency) T. F. Thiselton-Dyer (Thomas Firminger Thiselton-Dyer, 1848–1923), English writer of popular non-fiction books Thomas Henry Dyer (1804–1888), English historical and antiquarian writer