Incumbent Marie Gluesenkamp Perez (D) defeated John Braun (R) in the general election for Washington's 3rd Congressional District on November 3, 2026.

Perez was first elected in 2022, defeating Joe Kent (R) 50.1%–49.3%. In 2024, Perez defeated Kent 51.7%–47.9% and President Donald Trump (R) defeated Kamala Harris (D) 50.3%–47.0% in the 3rd District. The 3rd District was one of 23 U.S. House districts Democrats defended in 2026 that Trump won in 2024.

In the top-two primary, Perez and three other Democrats received a combined 55.9% of the vote. Braun and two other Republicans received a combined 42.0% of the vote. Brent Hennrich (D), who placed third with 15.3% of the vote, said he would not support Perez in the general election. In an interview with the Washington State Standard, Hennrich said, "I want [Perez] out of office ... I’ve told my supporters what I’m doing and I’ve told them to vote their conscience and that anyone they vote for should earn that vote." As of November 2026, major election forecasters rated the general election Toss-up, Lean Democratic, or Likely Democratic.

Perez was the founder and owner of an auto repair shop. Her campaign website said, "Marie is ranked as one of the most bipartisan lawmakers in the House and regularly works across the aisle to fix what's broken and make things easier for working families ... Marie was the kind of working-class Washingtonian left behind in this economy. The political establishment in DC ignored folks like her."

Braun had represented the 20th District in the Washington Senate since 2013. He was a U.S. Navy veteran and manufacturing executive. Braun's campaign website said, "John Braun spent 31 years in the submarine force, built a 350-employee company in Chehalis, and led the fight against Olympia's tax surge. Now he's running to bring that same discipline to Washington, D.C. ... In a submarine, you don't waste space. In manufacturing, you don't waste a dollar. In government, we shouldn't waste your money either."

As of November 2, 2026, Perez had raised $9.47 million and Braun had raised $3.31 million.

The outcome of this race affected the partisan balance of the U.S. House of Representatives in the 120th Congress. All 435 U.S. House districts were up for election.

At the time of the election, Republicans had a 219-214 majority with two vacancies in the U.S. House.