Expanse, Saskatchewan is an unincorporated area in the rural municipality of Lake Johnston No. 102, in the Canadian province of Saskatchewan. Expanse is located just to the south of Old Wives Lake on a grid road. The grid connects to Highway 2 near Ardill in south central Saskatchewan. Just to the south of Highway 2 is Lake of the Rivers. Expanse is too small to be enumerated as a separate entity during the census taking, so it was a part of the population given for rural municipality Lake Johnston No.