Idaho's 2nd congressional district is one of two congressional districts in the U.S. state of Idaho, in the eastern portion of the state. Beginning with the 2012 election, the district expanded westward and now includes most of Boise, the state capital and largest city.
After statehood in 1890, Idaho had a single seat in Congress through the 1910 election, a statewide at-large seat. Following the 1910 census, Idaho gained its second seat in the House; it was first contested in 1912, but the state did not immediately apportion into two districts. Through the 1916 election, both were statewide at-large seats. The first election in Idaho with two congressional districts was in 1918.
Following the 2010 census and redistricting, the 2nd district gained more territory in northeast Ada County, and now includes most of Boise, with all precincts north of Interstate 84. A significant increase in population directly west of Boise over the previous decade, in western Ada County and Canyon County, was responsible for the westward shift of the boundary. In Ada County, the 1st district continues to include Meridian, Eagle, and west Boise south of Interstate 84.
Other major cities in the 2nd district include Idaho Falls, Pocatello, Twin Falls, and Rexburg. The Church of Jesus Christ of Latter-day Saints has a strong presence in the district; a member of the LDS Church has represented this district continuously since 1951.
The district is currently represented by Mike Simpson, a Republican of Idaho Falls. A former dentist in Blackfoot, he was first elected in 1998; the seat opened when predecessor Mike Crapo successfully ran for the U.S. Senate.