Oregon's 3rd congressional district covers most of Multnomah County, including Gresham, Troutdale, and most of Portland east of the Willamette River (parts of Northwest and Southwest Portland lie in the 1st and 5th districts). It also includes the northeastern part of Clackamas County and all of Hood River County.
The district has been represented by Democrat Maxine Dexter since 2025. With a Cook Partisan Voting Index rating of D+24, it is the most Democratic district in Oregon and the second most Democratic district in the Pacific Northwest after Washington's 7th.
For the 118th and successive Congresses (based on redistricting following the 2020 census), the district contains all or portions of the following counties and communities:
Clackamas County (8)
Multnomah County (7)
The district was , sending its first representative to the .
Sources (official results only):
A special election was held on May 21, 1996 to fill the vacancy created when incumbent Ron Wyden resigned effective February 5, 1996 after winning a special election to the United States Senate. The winner of the election, Earl Blumenauer, served the remainder of Wyden's two-year term.
Before the 2002 redistricting, the whole of Multnomah County was included in the district; it lost southwest Portland to the 1st and 5th districts, but it gained most of its current portion of Clackamas County.