Kleiner (Hebrew: קליינר) is a German and Jewish surname, meaning "smaller":
Alfred Kleiner, Swiss physicist
Bruce Kleiner, American mathematician
Krista Arrieta Kleiner, Filipino-American TV actress/singer and host
Dick Kleiner, Hollywood columnist
Eugene Kleiner, Silicon Valley venture capitalist
Eugène-Louis Kleiner, Roman Catholic bishop
Israel Kleiner (biochemist) (1885-1966), biochemist
Israel Kleiner (mathematician), Canadian mathematician, professor at McGill University
John J. Kleiner, US Congressman from Indiana
Michael Kleiner, Israeli politician
Morris Kleiner, American professor of public affairs
Sergio Kleiner, Argentine soap opera star
