Barbara Jean Lee (née Tutt; born July 16, 1946) is an American politician and social worker who has served as a U.S. representative from California since 1998. A member of the Democratic Party, Lee represents California's 12th congressional district (numbered as the 9th district from 1998 to 2013 and as the 13th district from 2013 to 2023), which is based in Oakland and covers most of the northern part of Alameda County. According to the Cook Partisan Voting Index, it is one of the nation's most Democratic districts, with a rating of D+40.

Born and raised in Texas, Lee holds degrees from Mills College and the University of California, Berkeley. She started her career by working on the presidential campaign of Shirley Chisholm, and she later was involved with the Black Panther Party. After working as chief of staff for U.S. Representative Ron Dellums, Lee served in the California State Assembly from 1990 to 1996 and in the California State Senate from 1996 to 1998.

Lee was elected to the House of Representatives in a 1998 special election to succeed Dellums. A noted progressive, she chaired the Congressional Progressive Caucus from 2005 to 2009 and the Congressional Black Caucus from 2009 to 2011. In addition, she is the vice chair and a founding member of the Congressional LGBTQ+ Equality Caucus, a co-chair of the Congressional Cannabis Caucus, and a co-chair of the House Democratic Steering Committee. She has played a major role in the antiwar movement, notably in her vocal criticism of the Iraq War and for being the only member of Congress to vote against the authorization of use of force following the September 11 attacks.

Lee is a candidate for the United States Senate in the 2024 election to succeed late senator Dianne Feinstein.