The Rural Municipality of Flett's Springs No. 429 (2016 population: ) is a rural municipality (RM) in the Canadian province of Saskatchewan within Census Division No. 15 and Division No. 5.
The RM of Carrot River No. 429 was originally incorporated as a rural municipality on December 13, 1909. Its name was changed to the RM of Flett's Springs No. 429 on February 28, 1938.
The following urban municipalities are surrounded by the RM.
The following unincorporated communities are within the RM.
In the 2021 Census of Population conducted by Statistics Canada, the RM of Flett's Springs No. 429 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 Flett's Springs No. 429 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 Flett's Springs No. 429 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 Blaine Forsyth while its administrator is Tamie McLean. The RM's office is located in Melfort.