Steven Cowley, a theoretical physicist and international authority on fusion energy, became the seventh Director of the Princeton Plasma Physics Laboratory (PPPL) on July 1, 2018 and Princeton professor of astrophysical sciences on September 1, 2018. Prior to that he was president of Corpus Christi College and professor of physics at the University of Oxford in the United Kingdom (2016-2018). Cowley was chief executive officer of the United Kingdom Atomic Energy Authority (UKAEA) and head of the Culham Centre for Fusion Energy from 2008-2016. He earned his doctorate at Princeton University in astrophysical sciences in 1985 and was a staff scientist at PPPL from 1987 to 1993. From 2011-2016 he was a member of the UK Prime Minister's Council on Science and Technology. He is a Fellow of the Royal Society and of the Royal Academy of Engineering, and was knighted by the Queen of England in June 2018 for his role in fusion science.