Ted W. Lieu (; born March 29, 1969) is an American attorney, politician and retired military officer who has represented California's 36th congressional district in the U.S. House of Representatives since 2023. He represented the 33rd congressional district from 2015 to 2023. The district includes South Bay and Westside regions of Los Angeles, as well as Beverly Hills, Santa Monica, the Palos Verdes Peninsula, and Beach Cities.

Having emigrated from Taiwan at age 3, Lieu is one of 18 members of Congress who are naturalized U.S. citizens. He represented the 28th district in the California State Senate from 2011 to 2014, after being elected to fill the seat of deceased Senator Jenny Oropeza. From 2005 to 2010 he was a California State Assemblyman, representing the 53rd district, after being elected to fill the seat of deceased Assemblyman Mike Gordon.

Lieu served on active duty with the United States Air Force Judge Advocate General's Corps from 1995 to 1999. From 2000 to 2021 he served in the Air Force Reserve Command, and he attained the rank of colonel in 2015. House Democratic Leader Nancy Pelosi appointed Lieu assistant whip of the 115th Congress in 2017. He has been vice chair of the House Democratic Caucus since 2023.