Highway 5 is a major provincial highway in Saskatchewan, Canada. It begins in downtown Saskatoon and runs eastward to the Manitoba border near Togo, where it becomes Provincial Road 363. The highway is approximately 393 kilometres (244 mi) long. Between the early 1900s and 1976, Provincial Highway 5 was a trans-provincial highway travelling approximately 630 kilometres (390 mi) in length. At this time it started at the Alberta border in Lloydminster and travelled east to the Manitoba border.

Most of Highway 5 is a primary weight corridor for trucking. It is a two-laned highway for most of its length with only the section through Saskatoon being four lanes. Plans to eventually twin the highway from Saskatoon east to Highway 2 are in the works. Ten kilometres of twinning of the highway from Saskatoon east to 1.6 kilometres (1 mi) past Highway 316 is expected to be completed by the fall of 2027.

In the summer of 1970, the section of highway between Lloydminster and Saskatoon was designated to be a portion of the Yellowhead Highway. This section of highway maintained the Highway 5 designation until 1976, when it was redesignated as Highway 16 to maintain the same number through the four western provinces (Manitoba followed suit the following year, redesignating its section of the Yellowhead Highway from PTH 4 to PTH 16). This redesignation shortened the length of Highway 5 to its current length of 393 kilometres (244 mi).

Along the route are several heritage sites, an international bird watching area, saline lakes, as well as regional and provincial parks. Museums and historical markers commemorate the region's history along the highway.

The early Red River cart trail traversed the North-West Territory prairies between Portage la Prairie and Edmonton via Humboldt and Battleford, intersecting the future location of Highway 5 at Humboldt. The Dominion Government Telegraph Line was constructed in 1875, which was parallel to the future Highway 5. Both Red River Cart trail and telegraph line were abandoned in the 1920s.

January 3, 1910, was the first meeting of the RM of Blucher 343. In 1911, early homesteaders could choose to pay taxes at $9.00 per quarter section of land or working off $4.00 of this expense by constructing roads. A labourer and two horse team could earn 50 cents an hour and a four-horse team with a driver was allotted 70 cents an hour.

In 1925, Provincial Highway 5, the Evergreen Route, followed the surveyed rail line route of the Canadian Northern Railway, later the Canadian National Railway. Provincial Highway 5 had a western terminus at Lloydminster located on the Alberta–Saskatchewan border. When the province was surveyed, the road evolved from a dirt road to a gravel road. This was finally improved to an all-weather road known as Provincial Highway 5 from the Alberta–Saskatchewan border bypassing Saskatoon to the north, and continuing on to the Manitoba–Saskatchewan border. Just as the rail line went through Aberdeen, Warman, and Langham, so too did Provincial Highway 5.

In 1925, access from Saskatoon to Provincial Highway 5 was via Provincial Highway 12 which was a route due north of the city. The other connection was Provincial Highway 27 which travelled east and north from Saskatoon connecting to Provincial Highway 5 at the junction located at the town of Aberdeen. In the late 1950s and 1960s, the highway was straightened and widened. During this process, the current Saskatchewan Highway 5 connected Humboldt and Saskatoon in a more direct west and east highway. The old place names of Warman, Aberdeen, Vonda, Prudhomme, Dana, Bruno, and Carmel located on Provincial Highway 5 were no longer place names along Saskatchewan Highway 5. Now the Highway 2 concurrency was the only north–south stretch between Humboldt and Saskatoon and Meacham the only place name. On August 15, 1970, the Yellowhead was opened for the northern Trans-Canada route and the northwestern half of Provincial Highway 5 between Saskatoon and Lloydminster was designated as Highway 16, the Yellowhead route.