Stephen John Fossey is a British astronomer working at UCL Observatory, which is part of University College London (UCL). He is one of the three editors of The Observatory magazine. Fossey's research interests are in the interstellar medium, exoplanets and time-domain astronomy. Along with and , Fossey discovered in 2009 that the exoplanet HD 80606b (previously known from radial velocity) transits its host star. Fossey also discovered supernova SN 2014J, the closest supernova for each for several decades, in January 2014.