David Sen-Fu Chiu (Chinese: 邱信福, born April 2, 1970) is an American politician serving since 2021 as City Attorney of San Francisco. Previously, he served in the California State Assembly as a Democrat representing the state's 17th Assembly District, which encompasses the eastern half of San Francisco. Chiu was Chair of the Assembly Housing and Community Development Committee, a position he held from 2016 to 2021, and the former chair of the California Asian & Pacific Islander Legislative Caucus.

Chiu was born to Taiwanese American immigrants and earned three degrees from Harvard University. Prior to his election to the State Assembly, Chiu was the President of the San Francisco Board of Supervisors and Supervisor for District 3, encompassing the northeastern corner of the city, including Chinatown, Nob Hill, North Beach, Union Square, the Financial District, and Fisherman's Wharf. He was the first Asian American to serve as District 3 supervisor, the first Asian American to serve as board president, and the first supervisor elected to three consecutive terms as board president.

On September 29, 2021, San Francisco Mayor London Breed announced that she would appoint David Chiu to serve as the new City Attorney of San Francisco. After he left the Assembly, a special election was held to succeed him, which was won by District 6 supervisor Matt Haney.

The eldest child of Taiwanese American immigrant parents, Chiu was born in Cleveland, Ohio, and grew up in Boston, Massachusetts, where he attended Boston College High School. Chiu graduated from Harvard University, where he received a B.A. in government from Harvard College, a Master of Public Policy (M.P.P.) from the Kennedy School of Government, and a Juris Doctor degree from Harvard Law School.

In the mid-1990s, Chiu served as Democratic Counsel to the U.S. Senate Judiciary Committee's Constitution Subcommittee and aide to Senator Paul Simon to the Senate Budget Committee. After moving to San Francisco in 1996, Chiu worked as a law clerk for Judge James R. Browning of the United States Court of Appeals for the Ninth Circuit, as a criminal prosecutor at the San Francisco District Attorney's Office, and as a civil rights attorney at the Lawyers' Committee for Civil Rights. He later founded Grassroots Enterprise, an online communications technology company, and served as its chief operating officer and general counsel. He also served on the San Francisco Small Business Commission until he was elected supervisor in 2008.

Chiu first ran for elected office in 2008, when he ran for a seat on the San Francisco Board of Supervisors representing District 3. He was backed by incumbent supervisor Aaron Peskin as well as Kamala Harris, Mark Leno, Leland Yee, and Tom Ammiano.

On his first day in office on January 8, 2009, Chiu was elected to a two-year term as president of the Board of Supervisors. He was reelected board president on January 8, 2011.

Chiu was reelected to his second and final term as supervisor in 2012, winning over 75% of the vote. He was later reelected by his fellow supervisors to serve an unprecedented third term as president of the board on January 8, 2013. In addition to serving on the Board of Supervisors, Chiu also served as a member of the San Francisco Democratic County Central Committee.