Avenal is a city in Kings County, California, United States. Avenal is located 35 miles southwest of Hanford, at an elevation of 807 ft. It is part of the Hanford–Corcoran Metropolitan Statistical Area, which encompasses all of Kings County. In area, it is the fourth-largest city in Kings County. The population was 15,505 in the 2010 census, which includes inmates at the Avenal State Prison, the first prison actively solicited by a community in the state of California.