can refer to numerous people:
- Boyd Clack, Welsh writer, actor and musician.
- Brenda Clack, politician.
- Barbara Cooper Clack, world water skiing champion
- Darryl Clack, player of American football for the Dallas Cowboys in 1986
- H. Earl Clack, who has two Historic Places in Montana named after him.
- Michael Clack, leader of the Chalk Farm Salvation Army Band
- Jennifer A. Clack, paleonthologist and evolution specialist.
- Jill Elizabeth Clack, member of the Greater London Council from 1981 to 1986
- Jim Clack, player of American football.
- Kris Clack, basketball player.
- Peter Clack, rock and roll drummer.
- Spencer Clack, pioneer who settled in Sevierville, Tennessee
- William Clack, committee chair of the Greater London Council from 1977 to 1981
- William Sydney Clack, member of the Greater London Council from 1970 to 1981
- Zoanne Clack, television producer, writer, story editor and actress.
- Clack Stone, militia captain during the 1832 Black Hawk War.