Dennett is a surname. Notable people with the surname include:
Daniel Dennett (1942–2024), American philosopher, writer, and cognitive scientist
Fred Dennett (1863–1928), American politician
Fred A. Dennett (1849–1920), American politician
Edward George Dennett (1879–1937), English cricketer
Lydia Neal Dennett (1798–1881), American abolitionist and suffragist
Mary Dennett (1872–1947), American birth control activist
Pruett Mullens Dennett (1899–1918), British military aviator
R. E. Dennett, English trader and author
Russell Dennett, British musician (The Human League)
Tyler Dennett (1883–1949), American historian
