18 (2016 population: 150) is a rural municipality (RM) in the Canadian province of Saskatchewan within Census Division No.

This name was once further rearranged to form Treelon, a post office which operated in the municipality until 1945.

In the 2021 Census of Population conducted by Statistics Canada, the RM of Lone Tree No.

18 is governed by an elected municipal council and an appointed administrator that meets on the third Wednesday of every month.

[3] The reeve of the RM is Roger Goodall while its administrator is Marla Shirley.