Ontario Highway 138

Ontario Highway 138

King's Highway 138, commonly referred to as Highway 138, is a provincially maintained highway in eastern portion of the Canadian province of Ontario. It extends from former Highway 2 in Cornwall, north to Highway 417 east of Casselman. Highway 138 provides access to the Seaway International Bridge, connecting Cornwall with Massena, New York. The highway is 38.7 km (24.0 mi) in length.

Highway 138 was first established in 1967, connecting Highway 2, now Vincent Massey Drive, with Highway 43 in Monkland. By the mid-1970s, the route had been extended north to meet with the newly opened Highway 417. Since then it has remained unchanged.