Leiner is a surname. Notable people with the surname include:
Benjamin Leiner, American boxer
Božidar Leiner, Croatian Jewish resistance fighter
Danny Leiner, American film director
Gershon Henoch Leiner, Polish Jewish theologian
Laura Leiner, Hungarian writer
Mordechai Yosef Leiner, Polish Jewish theologian
Shmuel Shlomo Leiner, Polish Jewish theologian
Simcha Leiner, American Orthodox Jewish singer