Lack is a surname. Notable people with the surname include:

• Andrew Lack (author) (born 1953), English biologist and author
• Andrew Lack (executive) (born 1947), chairman of NBC News and MSNBC
• David Lack (1910–1973), British ornithologist and biologist
• Eddie Lack (born 1988), Calgary Flames goaltender
• Fredell Lack (1922–2017), American classical violinist
• James J. Lack (born 1944), New York politician and judge
• Ken Lack (1934–2001), Jamaican record producer
• Mercie Lack (1894-1985), British photographer
• Portia Lack (born 1961), American handball player
• Simon Lack (1913–1980), Scottish actor
• Stephen Lack (born 1946), Scottish painter and actor
• Théodore Lack (1846–1921), French classical pianist and composer