Thomas Allen may refer to:

• Thomas Allen, Chicago Alderman
• Thomas Allen (1542–1632), English mathematician.
• Sir Thomas Allen, Bt, 17th century English Member of Parliament.
• Rev. Thomas Allen, American revolutionary.
• Thomas Allen (1840–1904), American professional boxer.
• Thomas Allen (1849–1924), American artist.
• Sir Thomas Allen (born 1944), British baritone singer.
• Thomas Allen and Son Limited, Canadian publishing firm.
• Thomas Allen - voice actor
• Thomas Allen (politician) A Maine politician
• Thomas B. Allen illustrator
• Thomas B. Allen (Author) Author, Historian
• Thomas J. Allen MIT professor, Economist
• Thomas S. Allen Early 20th century U.S. composer