Montana's second congressional district is a congressional district in the United States House of Representatives that was apportioned after the 2020 United States census. The first candidates ran in the 2022 elections for a seat in the 118th United States Congress.

Geographically, the district is the second-largest by land area, after Alaska's at-large congressional district, and the largest by land area in the contiguous United States. It is also the largest district in the U.S. to not contain an entire state.

From 1913 to 1993, Montana had two congressional seats. From 1913 to 1919, those seats were elected statewide at-large on a general ticket. After 1919, however, the state was divided into geographical districts. The 2nd covered the eastern part of the state, including Billings, Glendive, Miles City, and other towns. After 1993, the second seat was eliminated and the remaining seat was elected at-large.

After the release of the 2020 United States census results, Montana regained its 2nd congressional district.^[3] On November 12, 2021, Montana's Districting and Apportionment Commission approved a new congressional map in which the 2nd congressional district would cover the eastern portion of Montana, in a configuration similar to the 1983–1993 map. However, the state capital, Helena, which had historically been in the 1st district, was drawn into the 2nd district.^[4]

Except for the city of Helena and some Native American areas like Big Horn County and part of longtime national bellwether Blaine County, the district is powerfully Republican. Overall, it is the third-most-Republican district in the West, with a Cook Partisan Voting Index of R+16, and it voted for Donald Trump by nearly 27 percentage points in the 2020 presidential election.

• Montana's congressional districts
• List of United States congressional districts