Karen Lorraine Jacqueline Speier (born May 14, 1950) is an American lawyer and politician who served as the U.S. representative for California's 14th congressional district, serving in Congress from 2008 to 2023. A member of the Democratic Party, Speier represented much of the territory that her political mentor, Leo Ryan, represented.

In 1978, while working as his aide, Speier survived five gunshot wounds when Ryan was assassinated during the Jonestown massacre. Speier was a member of the California State Senate, representing parts of San Francisco and San Mateo counties. On April 8, 2008, she won the special election for the vacated United States House of Representatives seat of the late Congressman Tom Lantos. In 2021, she announced that she would not seek reelection in the 2022 midterm elections.