Marion Lee Johnson is an American mathematician who was crucial or very important to the landing of the Apollo 11 mission. She was a mathematician on the Boeing/NASA team, where she worked in preparing data for the vehicle impact trajectories. Her perfect score over 20 successful missions earned her a place on the Apollo/Saturn V Roll of Honor. After completion of the project, she worked for Pfizer for 26 years. She currently lives in New Jersey, where she works at the Branford Hall Career Institute as a Computer and Security Instructor.