Idaho will hold its statewide primary elections on May 19, 2026, with contests for governor, one U.S. Senate seat and both of the state's U.S. House seats on the ballot. Polls will be open from 8 a.m. to 8 p.m. local time, as Idaho joins five other states voting that day.

Governor Brad Little, 72, a rancher, is campaigning for a third term and faces seven challengers in the Republican primary. Only one of those challengers, Ron James, holds elected office, serving as a county commissioner.

Mark Fitzpatrick, a retired police officer and business owner who describes himself as a "bold culture warrior," has out-fundraised the other Republican challengers. Fitzpatrick accused Little of being a "traitor" for allowing an "illegal immigrant invasion" on his watch. In 2025, he organized a "Hetero Awesomeness Fest" in response to LGBTQ Pride events.

Four candidates are competing in the Democratic primary for governor. Former public defender Terri Pickens has out-raised her competitors by a double-digit factor.

Little previously won the 2022 Republican gubernatorial primary against Lieutenant Governor Janice McGeachin, who had been endorsed by President Donald Trump. In 2021, while Little was out of state, McGeachin signed an executive order banning mask mandates, which Little repealed upon his return. In 2025, Little signed into law a bill passed by the Idaho legislature banning mask mandates.

Former Idaho governor Jim Risch is seeking a fourth term in the U.S. Senate. In January 2026, Trump endorsed Risch, calling him one of his "strongest allies" in the Senate. Risch's political action committee has spent more than $1 million in the Republican Senate primary, according to Federal Election Commission records, while his closest rival, Josh Roy, documented roughly $23,500 in campaign expenses. On the Democratic side, only David Roth, a nonprofit worker, reported more than $5,000 in contributions during the last reporting period. Roth is the first openly gay candidate to receive a statewide nomination in Idaho.

In Idaho's first congressional district, Republican Russ Fulcher, a businessman, faces two challengers, neither of whom reported substantial campaign contributions to the Federal Election Commission as of April 29, 2026. Kaylee Peterson raised more funds than her competitors heading into the Democratic primary.

In the second congressional district, incumbent Mike Simpson, a former dentist who has held the seat since 1999, is seeking a 15th term. Simpson has spent more than $600,000 on his re-election campaign, according to the Idaho Capital Sun. Challenger Perry Shumway raised $5,291.98 by the end of April 2026, according to Federal Election Commission records. Democrat Ellie Gilbreath is running unopposed after her only competition withdrew from the race, according to her website.

All incumbents for Idaho's U.S. House and Senate seats have received Trump's endorsement ahead of the primaries. Idaho has not elected a Democrat to the U.S. Senate since 1974, and has not elected a Democratic governor since 1995. The last Democrat elected to federal office from the state was U.S. Representative Walt Minnick in 2008, who served a single term.