Sara Seager (born July 21, 1971) is a Canadian-American astronomer and planetary scientist. She is a professor at the Massachusetts Institute of Technology and known for her work on extrasolar planets and their atmospheres. She is the author of two textbooks on these topics. She has been recognized for this research by Popular Science, Discover Magazine, Nature, and TIME Magazine. Seager was awarded a MacArthur Fellowship in 2013 citing her theoretical work on detecting chemical signatures on exoplanet atmospheres and developing low-cost space observatories to observe planetary transits.