Martinsdale Colony is a Hutterite community and census-designated place (CDP) in Wheatland County, Montana, United States. As of the 2020 census, Martinsdale Colony had a population of 97. It is on the western edge of the county, bordered to the west by Meagher County and northeast of the unincorporated community of Martinsdale. The Musselshell River forms the southern edge of the CDP.
U.S. Route 12 runs through the southern part of the CDP, leading east to Harlowton, the Wheatland county seat, and west to White Sulphur Springs.
The community was first listed as a CDP prior to the 2020 census.
The community is zoned to Harlowton Public Schools.