Dayman is a surname. Notable people with the surname include:
Clem Dayman (1892–1967), Australian rules footballer Edward Dayman (1807–1890), English clergyman and hymn writer Greg Dayman (born 1947), New Zealand field hockey player Ivan Dayman (1920–1989), Australian record producer and band manager Les Dayman (1901–1977), Australian rules footballer Leslie Dayman (1933–2023), Australian actor Marlene Dayman (born 1949), Australian swimmer