Thomas Howell may refer to:
- Thomas Howell (curler) (born 1994), American curler
- Thomas Howell (poet) (fl. 1568), English poet
- Thomas Howell (bishop) (1588–1650), Bishop of Bristol, 1644–1645
- Thomas Bayly Howell (1767–1815), English lawyer and writer who edited and lent his name to Howell's State Trials
- Thomas Jones Howell (1793–1858), son of Thomas Bayly Howell and co-editor of Howell's State Trials
- Thomas J. Howell (politician) (1830s–?), American state legislator in Missouri, possible namegiver to Howell County
- Thomas J. Howell (botanist) (1842–1912), American botanist
- Thomas Raymond Howell, American ornithologist
- C. Thomas Howell (born 1966), American actor and film director
- Tommy Howell, rugby league footballer who played in the 1890s and 1900s
- Tom Howell (cricketer) (born 1987), English cricketer
- Thomas Howell, Welsh merchant draper who bequeathed money to Howell's School, Denbigh