Delevan (formerly, Delavan and Del Evan) is an unincorporated community in Colusa County, California, 3.5 miles (5.6 km) south of Norman and 5 miles (8.0 km) north of Maxwell. It lies at an elevation of 92 feet (28 m). A post office was established at Delevan in 1902, closed in 1917, and reopened in 1922.