100 (2016 population: 226) is a rural municipality (RM) in the Canadian province of Saskatchewan within Census Division No.

Geographical features in the RM include the Dirt Hills, Watson Reservoir, Avonlea Badlands, and Avonlea Creek.

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

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

[3] The reeve of the RM is Ken Miller while its administrator is Jaimie Paranuik.