This year’s filing deadline for candidates running for the U.S. House of Representatives in Oklahoma was April 3, 2026.

Eight primaries — four Democratic and four Republican — are contested this year. In total, there were five contested primaries in 2024, four in 2022, six in 2020, nine in 2018, eight in 2016, and seven in 2014.

Three incumbents — all Republicans — are running in those contested primaries. There were three incumbents in contested primaries in 2024, three in 2022, three in 2020, three in 2018, five in 2016, and three in 2014.

The 1st Congressional District is the only open district this year. The district’s incumbent Rep. Kevin Hern (R) is running for the U.S. Senate in Oklahoma. There were no open districts in 2024, one in 2022, none in 2020, one in 2018, none in 2016, and one in 2014.

The district has attracted a high number of candidates. Twelve candidates — one Democrat and 11 Republicans — are running for the 1st Congressional District, the most candidates running for a district this year.

Twenty-seven candidates — nine Democrats and 18 Republicans — are running for Oklahoma’s five congressional districts. That’s 5.4 candidates per district. There were 3.6 candidates per district in 2024, 5.6 in 2022, 5.4 in 2020, 7.2 in 2018, four in 2016, and 4.4 in 2014.

Candidates filed to run in the Republican and Democratic primaries in all five districts, meaning no districts are guaranteed to either party.

Oklahoma is holding U.S. House primaries on June 16, 2026. If needed, Oklahoma will hold runoff elections on Aug. 25, 2026.

In Oklahoma, winners in primary contests are determined by majority vote. The top two candidates participate in a runoff election if no candidate wins a majority in the first round of balloting.