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 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 of Lake Johnston No. 102.