The Rural Municipality of Happy Valley No. 10 (2016 population: ) is a rural municipality (RM) in the Canadian province of Saskatchewan within Census Division No. 2 and Division No. 2. Located in the southeast portion of the province, it is adjacent to the United States border, neighbouring Daniels County and Sheridan County in Montana.
The RM of Happy Valley No. 10 incorporated as a rural municipality on January 1, 1913.
The following unincorporated communities are within the RM.
There are three sites on Canadian Register of Historic Places in the RM:
In the 2021 Census of Population conducted by Statistics Canada, the RM of Happy Valley No. 10 had a population of living in of its total private dwellings, a change of from its 2016 population of . With a land area of , it had a population density of in 2021.
In the 2016 Census of Population, the RM of Happy Valley No. 10 recorded a population of living in of its total private dwellings, a change from its 2011 population of . With a land area of , it had a population density of in 2016.
The RM of Happy Valley No. 10 is governed by an elected municipal council and an appointed administrator that meets on the second Tuesday of every month. The reeve of the RM is Rodney Sjogren while its administrator is Leanne Totton. The RM's office is located in Big Beaver.