King's Highway 141, commonly referred to as Highway 141, is a provincially maintained highway in the Canadian province of Ontario. Its western terminus is at Highway 400 south of Horseshoe Lake in Seguin Township while its eastern terminus is at Highway 11 near Port Sydney. The route was designated in 1974 when Highway 532 was renumbered and upgraded from a secondary highway to a King's Highway. The route has remained generally unchanged since, though it was extended by several kilometres on October 7, 2003 when Highway 400 was extended north of Mactier.