Wilmarth is a surname. Notable people with the surname include:
Anna Wilmarth Ickes (1873–1935), American politician and activist Christopher Wilmarth (1943–1987), American sculptor Dick Wilmarth (died 2018), American miner and dog racer Lemuel Wilmarth (1835–1918), American painter William H. Wilmarth (1904–1999), American sound engineer