Lett may refer to:

  • Lett, archaic word for Latvian
    • Lettish, another name for the Latvian language

Lett as a surname may refer to the following:

  • Barbara Lett-Simmons (born 1927), American politician
  • Benjamin Lett (1813–1858), Irish-Canadian filibusterer
  • Dan Lett, Canadian actor
  • David Lett (born 1939), founder and winemaker for The Eyrie Vineyards in Oregon
  • Evelyn Lett (1896-1999), Canadian women's rights pioneer
  • Leon Lett (born 1968), former American Football defensive tackle
  • Michael Lett (born 1987), Rugby League player who plays for the Sydney Roosters in the National Rugby League (NRL) competition
  • Sherwood Lett (1895–1964), Canadian soldier, lawyer, diplomat, and jurist
  • Lett's Brewery (officially Mill Park Brewery), a beer manufacturer based in Enniscorthy, County Wexford, Ireland