Amsterdam is a census-designated place (CDP) in Gallatin County, Montana, United States.

According to the United States Census Bureau, the CDP has a total area of 2.7 square miles (7.0 km2), all land.

The town is bordered by the Camp Creek on the west and Valley Ditch to the north.

Though part of the immense Gallatin National Forest, there are few trees in the area.

The railroad changed the name to Amsterdam because of the large number of Dutch settlers.