King's Highway 417, commonly referred to as Highway 417 and as the Queensway through Ottawa, is a 400-series highway in the Canadian province of Ontario. It connects Ottawa with Montreal via A-40, and is the backbone of the highway system in the National Capital Region. Within Ottawa, it forms part of the Queensway west from Highway 7 to Ottawa Road 174. Highway 417 extends from the Quebec border, near Hawkesbury, to Arnprior, where it continues westward as Highway 17. Aside from the urban section through Ottawa, Highway 417 passes through farmland that dominates much of the fertile Ottawa Valley.

The 400-series highways are a network of controlled-access highways in the Canadian province of Ontario, forming a special subset of the provincial highway system. They are analogous to the Interstate Highway System in the United States or the Autoroute system of neighbouring Quebec, and are regulated by the Ministry of Transportation of Ontario (MTO). The 400-series designations were introduced in 1952, although Ontario had been constructing divided highways for two decades prior. Initially, only Highways 400, 401 and 402 were numbered; other designations followed in the subsequent decades. The network is situated almost entirely in Southern Ontario, although Highway 400 extends into the more remote northern portion of the province.