Sider is the surname of several people:Ron Sider (born 17 September 1939), Canadian-born American theologian and social activist. Theodore Sider ('Ted'), American philosopher specializing in metaphysics and philosophy of language. Lizzie Sider (born 1997 or 1998) (Elizabeth Sophia Sider), American singer-songwriter. Gerald Sider, anthropologist. Sider, an automated code review service. See also North Sider, (foaled in 1982), American thoroughbred racehorse.