The 2008 United States Senate election in Oregon was held on November 4, 2008. Incumbent Republican U.S. Senator Gordon H. Smith sought reelection to a third term. Smith was the only Republican Senator from the West Coast and the only Republican holding statewide office in Oregon. He was opposed by Democrat Jeff Merkley, the Speaker of the Oregon House of Representatives, and David Brownlow of the Constitution Party of Oregon. Merkley won by a narrow margin, with Smith not conceding until two days after the election. Merkley became the first Democrat to win this seat since 1960. And since Smith was the only Republican holding statewide office in Oregon at the time, this was the first time since 1860 that no Republicans won or held statewide office in Oregon. Jeff Merkley's inauguration marked the first time since 1967 that Democrats held both of Oregon's United States Senate seats.

Peter Anthony DeFazio is an American politician who served as the U.S. representative for Oregon's 4th congressional district from 1987 to 2023. He is a member of the Democratic Party and is a founder of the Congressional Progressive Caucus. A native of Massachusetts and a veteran of the United States Air Force Reserve, he previously served as a county commissioner in Lane County, Oregon. On December 1, 2021, DeFazio announced he would not seek reelection in 2022.