King's Highway 420, commonly referred to as Highway 420, is a 400-series highway in the Canadian province of Ontario that connects the Queen Elizabeth Way (QEW) with downtown Niagara Falls. It continues east as a limited-access expressway named Niagara Regional Road 420 to connect with the Rainbow Bridge international crossing between Canada and the United States over the Niagara River; this was part of Highway 420 until 1998. West of the QEW, the freeway ends at an at-grade intersection with Montrose Road (Niagara Regional Road 98). The highway has a speed limit of 80 km/h, making it the only 400-series highway to have a speed limit less than 100 km/h for its entirety.