The 2018 United States House of Representatives elections in Oklahoma were held on November 6, 2018, to elect the five U.S. representatives from the state of Oklahoma, one from each of the state's five congressional districts. The elections coincided with other elections to the House of Representatives, elections to the United States Senate and various state and local elections. Primary elections were held on June 26 and runoff elections were held two months later on August 28. The state congressional delegation changed from 5-0 majority for Republicans to a 4-1 Republican majority. This is the first time since the 2012 election that Democrats held a seat in the state, and as of 2022, the last election in which Democrats won any house race in Oklahoma.