The Rural Municipality of Rosemount No. 378 (2016 population: ) is a rural municipality (RM) in the Canadian province of Saskatchewan within Census Division No. 12 and Division No. 6.
The RM of Rosemount No. 378 incorporated as a rural municipality on December 12, 1910.
The following unincorporated communities are within the RM.
In the 2021 Census of Population conducted by Statistics Canada, the RM of Rosemount No. 378 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 Rosemount No. 378 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 Rosemount No. 378 is governed by an elected municipal council and an appointed administrator that meets on the second Wednesday of every month. The reeve of the RM is Albert L. Kammer while its administrator is Kara Kirilenko. The RM's office is located in Landis.