Thomason is a patronymic surname meaning "son of Thomas" or a misspelling of the French surname Thomasson, Thomesson "little Thomas". Thomason is an American surname. There are varied spellings. Notable people with the surname include:
- Art Thomason (1889–1944), American baseball player
- Bob Thomason, basketball coach at the University of the Pacific.
- Bobby Thomason (1928–2013), American football player
- Sergeant Clyde A. Thomason (1914–1942), United States Marine and Medal of Honor awardee
- Dustin Thomason, American writer
- George Thomason (died 1666), English book collector
- Harry Thomason (born 1940), American film and television producer
- James Thomason (1804–1853), British Lieutenant-Governor of the North-Western Provinces in India
- Jasin Thomason (born 1976), guitarist for American rock band The Ataris
- Jeff Thomason (born 1969), American football tight end
- Jim Thomason (1920–2007), American football halfback
- John Thomason (1893–1944), United States Marine and author
- Larry Thomason (1948–2003), American politician
- Mackenzie Thomason, Canadian politician
- Marsha Thomason (born 1976), English actress
- R. Ewing Thomason (1879–1973), American politician and Speaker of the Texas House of Representatives
- Robert Wayne Thomason (1952–1995), American mathematician
- Roy Thomason (born 1944), British Conservative Party politician
- Sarah Thomason, American linguist
- Theresa Thomason, American gospel singer
- Trent Thomason (born 1972), Christian keyboardist and songwriter
- Yeoville Thomason (1826–1901), Birmingham architect
- Linda Bloodworth-Thomason (born 1947), American writer and television producer
- Lorene Thomason Coates, Democratic member of the North Carolina General Assembly
- Sir Wilfred Thomason Grenfell (1865–1940), medical missionary to Newfoundland and Labrador