Andrew Christopher Fabian, OBE, FRS (born 20 February 1948) is a British astronomer and astrophysicist. He has been Director of the Institute of Astronomy, University of Cambridge since 2013. He was a Royal Society Research Professor at the Institute of Astronomy, Cambridge from 1982 to 2013, and Vice-Master of Darwin College, Cambridge from 1997 to 2012. He was the President of the Royal Astronomical Society from May 2008 through to 2010.
He is an Emeritus Professor of Astronomy at Gresham College, a position in which he delivered free public lectures within the City of London between 1982 and 1984. He was also editor-in-chief of the astronomy journal Monthly Notices of the Royal Astronomical Society. He was educated at King's College London (BSc, Physics) and University College London (PhD).
His current areas of research include galaxy clusters, active galactic nuclei, strong gravity, black holes and the X-ray background. He has also worked on X-ray binaries, neutron stars and supernova remnants in the past. Much of his research involves X-ray astronomy and high energy astrophysics. His notable achievements include his involvement in the discovery of broad iron lines emitted from active galactic nuclei, for which he was jointly awarded the Bruno Rossi Prize. He is author of over 1000 refereed articles and head of the X-ray astronomy group at the Institute of Astronomy. Fabian was awarded the Dannie Heineman Prize for Astrophysics by the American Astronomical Society in 2008 and the Gold Medal of the Royal Astronomical Society in 2012.
In 2016 he was elected as a foreign associate of the National Academy of Sciences and awarded the Bruce Gold Medal by the Astronomical Society of the Pacific.