It begins in Saskatoon at the intersection of Idylwyld Drive and Highway 11 north[2] (formerly beginning further south at the intersection with 22nd Street), initially running north on Idylwyld Drive concurrently with Highway 11 and Highway 16.

Just outside Saskatoon's northern city limits, Highway 11 exits northeast from Idylwyld Drive and Highway 12 begins and travels north, passing through the city of Martensville.

[1] Provincial Highway 12 was originally the designated route which connected Saskatoon and Prince Albert, following present-day Highway 12 to the Hepburn area, then following present-day Highway 312 to Rosthern, before continuing northwest to Prince Albert.

[4][5] In the mid-1950s, the route was renumbered to Highway 11;[6] however, in the 1960s Highway 11 was realigned to follow a more direct route to Rosthern through Warman and Hague.

[8] In the 1970s, Highway 12 was extended north to Shell Lake.