Summer Lynn Lee (born November 26, 1987) is an American politician and community organizer serving as the U.S. representative for Pennsylvania's 12th congressional district since 2023. A member of the Democratic Party, Lee served as a member of the Pennsylvania House of Representatives for the 34th district from 2019 to 2022. With the support of the local chapter of the Democratic Socialists of America, she defeated incumbent Paul Costa in the 2018 Democratic primary election with over 67% of the vote. Lee was the first black woman to represent Southwestern Pennsylvania in the state legislature.

Lee was the Democratic nominee in the 2022 election to represent Pennsylvania's 12th congressional district in the United States House of Representatives. She won the primary by less than 1% of the vote over her closest opponent, Steve Irwin, the chair of the State Advisory Committee for the United States Commission on Civil Rights. She won the general election, and became the first Black woman from Pennsylvania in the House of Representatives.

Lee was a member of Democratic Socialists of America, but left DSA before winning office after disagreements with the Pittsburgh DSA chapter.