Debra Ann Fischer (born 1953) is an American astronomer and professor emerita at Yale University. She is known for her work in the discovery and characterization of exoplanets using the radial velocity method.

Fischer has been involved in the detection of hundreds of exoplanets and has contributed to the development of high-precision spectrographs used in exoplanet research.

Fischer received her degree in nursing from the University of Iowa in 1975, a masters of science in physics from San Francisco State University in 1992, and her PhD in astrophysics from the University of California, Santa Cruz in 1998.

Following her PhD, Fischer worked as a postdoctoral researcher at the University of California, Berkeley. She was a faculty member at San Francisco State University from 2003 to 2008 before joining Yale University in 2009. She was a Fellow at the Radcliffe Institute for Advanced Study from 2009 – 2010.

At Yale, Fischer held a primary appointment in Astronomy, and secondary appointments in Earth & Planetary Sciences, and Statistics & Data Science. Fischer served as Dean of Academic Affairs from 2018 to 2021. Fischer served as Division Director of Astronomy at the National Science Foundation from 2021 - 2023.

Fischer began exoplanet research in 1997 using Doppler spectroscopy and was part of the team that discovered the first known multi-planet system around the star Upsilon Andromedae in 1999.

She quantified a correlation between the chemical composition of host stars and the formation of orbiting gas giant planets.

She co-led the N2K Consortium with Gregory Laughlin, detecting dozens of exoplanets around metal-rich stars at Keck Observatory, the Subaru telescope and the Magellan Telescopes.