William Sidney Hatfield (May 15, 1891 or 1893 – August 1, 1921), was a West Virginia law enforcement officer noted for his involvement in bitter labor disputes, on the side of labor, during the Coal Wars of the early 20th Century. Hatfield was police chief of Matewan, West Virginia during the Battle of Matewan, a shootout that followed a series of evictions carried out by detectives from the Baldwin–Felts Detective Agency. He was indicted on murder charges stemming from the conflict and was shot on the courthouse steps by Baldwin-Felts detectives.