MaryLouise Isaacson (born November 15, 1970) is an American politician serving as a member of the Pennsylvania House of Representatives from the 175th district since 2019.

Isaacson was born on November 15, 1970, in Rockville Centre, New York. She graduated from Massapequin High School in 1988. In 1990, Isaacson received her Associate degree in early childhood development from State University of New York at Farmingdale. She earned a Bachelor of Science in political science from State University of New York at Oneonta in 1992.^[1]

From 2006 to 2018, Isaacson served as chief of staff to Pennsylvania State Representative Michael H. O'Brien. At the same time, she served on the Democratic Committee of Philadelphia. Isaacson also served on the Democratic State Committee of Pennsylvania starting in 2010.^[1] Because of health issues, O'Brien filed paper work to remove his name from the 2018 general election ballot. Isaacson was chosen by the Philadelphia Democratic Committee to replace him.^[2] She won the general election that year and was reelected in 2020 and 2022.^[1]

Isaacson and her husband, Chris, have two children. The family lives in the Northern Liberties neighborhood of Philadelphia^[3]