Paul Fairchild is Associate Professor and Lecturer in Medicine at the Dunn School and was Co-Director of the Oxford Stem Cell Institute from 2008-2015. He first came to Oxford in 1987 to undertake a DPhil in the Nuffield Department of Surgery, working with Jonathan Austyn who had been a student in the Dunn School with Siamon Gordon.

Fairchild worked on the role of dendritic cells in preventing autoimmunity through the induction of tolerance in T cells. He then went to the Department of Pathology at Cambridge for post-doctoral research on how this system fails in multiple sclerosis. There he met Hermann Waldmann: when Waldmann succeeded Henry Harris as head of the Dunn School he invited Fairchild to join his group in Oxford.

Fairchild developed a technique for differentiating embryonic stem cells into dendritic cells. In 2008 he became the founding director of the Oxford Stem Cell Institute, which brings together 50 laboratories in 17 departments across the university, in collaborative projects initially supported by the Oxford Martin School. He has also been editor of the Dunn School magazine, Fusion, for ten years.