Lumsden No. 189 is a rural municipality (R.M.) located in south-western Saskatchewan, Canada. It is located in Division No.6.
Lumsden No. 189 completely surrounds the town of Lumsden. Other communities that are located at its perimeters include Buena Vista, Craven, Disley, Lumsden Beach, and Regina Beach. It is named after Hugh D. Lumsden who was the chief surveyor on the project in 1887 to take the railroad from Regina to Prince Albert. The R.M. was incorporated in 1912. According to the Canada 2001 Census, the population was 1,646.