California's 45th congressional district

California's 45th congressional district is a congressional district in the U.S. state of California currently represented by Republican Michelle Steel. It was one of 18 districts that would have voted for Joe Biden in the 2020 presidential election had they existed in their current configuration while being won or held by a Republican in 2022.

The 45th district was created as a result of the redistricting cycle after the 1980 census.

The district is based in Orange and Los Angeles counties and includes all of Garden Grove, Westminster, Cerritos, Buena Park, Placentia, Hawaiian Gardens, Cypress, Fountain Valley, Artesia, Los Alamitos, Rossmoor, and La Palma, as well as parts of Brea, Lakewood, and Fullerton.

In 2018, incumbent Representative Mimi Walters competed against a field of four Democrats and an independent candidate in the primary election for the 2018 midterm elections. On February 25, 2018, UC Irvine (UCI) assistant law professor Dave Min received the endorsement of the California Democratic Party.

Min, former White House senior technology advisor Brian Forde, former legislative assistant to Sherrod Brown (D-OH) Kia Hamadanchy, UCI law professor Katie Porter, and UCI business professor John Graham ran in the "top two" primary in June 2018. Walters and Porter placed first and second and advanced to the general election in November.

On November 14, 2018, 8 days after polls closed, Dave Wasserman, then the House Editor for The Cook Political Report, projected that Porter had won the general election.

In 2024, the election in this district is expected to be one of the state's most competitive. In its current form after the 2020 redistricting, the district has a significant presence of Asian American voters.