Mary-Louise Isaacson (born November 15, 1970) is a Democratic member of the Pennsylvania House of Representatives. She has represented the 175th district since 2019. Isaacson earned a bachelor's degree in Political Science from State University of New York at Oneonta, and an A.S. in Early Childhood Education from State University of New York at Farmingdale. She served as a coordinator of zoning and land practice at a Philadelphia law firm. Isaacson was a member of the Democratic State Committee for 14 years. She served as chief of staff to representative Michael H. O'Brien for 12 years. Isaacson was chosen as the Democratic nominee for O'Brien's seat by Philadelphia ward leaders after O'Brien withdrew from the race in July 2018. In November 2018, she was elected state representative for th