Fassett as a surname may refer to:
- Norman C. Fassett (1900–1954) expert on aquatic plants, professor of botany and curator of the Herbarium at the University of Wisconsin–Madison
- Cornelia Adele Strong Fassett (1831–1898), American painter
- Francis Fassett (1823–1908), American architect in Portland, Maine
- Jacob Sloat Fassett (1853–1924), U.S. Representative from New York, 1905–1911, wealthy businessman.
- Kaffe Fassett (born 1937), American textile artist
As a place name, it may refer to:
- Fassett Square in Dalston, London Borough of Hackney, England
- Fassett, Quebec in Canada (named after Jacob Sloat Fassett.)