Margaret J. Geller (born December 8, 1947) is an American astrophysicist at the Center for Astrophysics | Harvard & Smithsonian.

Geller completed her doctoral dissertation, titled "Bright galaxies in rich clusters: a statistical model for magnitude distributions", under the supervision of James Peebles.

Her long range goals are to discover what the universe looks like and to understand how the patterns we observe today evolved.

In the 1980's, she made pioneering maps of the nearby universe,[7] which included the Great Wall[8] and was the inspiration for Jasper Johns 2020 piece called Slice.

A later 40-minute film, So Many Galaxies...So Little Time, contains more sophisticated prize-winning (IEEE/Siggraph) graphics and was on display at the National Air and Space Museum.

[15] Popular articles by Geller appear with those by Robert Woodrow Wilson, David Todd Wilkinson, J. Anthony Tyson and Vera Rubin in Beyond Earth: Mapping the Universe[16] and with others by Alan Lightman, Robert Kirshner, Vera Rubin, Alan Guth, and James E. Gunn in Bubbles, Voids and Bumps in Time: The New Cosmology.