Catherine Greenhill was an undergraduate at the University of Queensland, in Brisbane, Australia, where she completed a Bachelor of Science followed by an MSc by research, supervised by Anne Street. Her doctoral research was performed at the Mathematical Institute, University of Oxford, under the supervision of Peter Neumann. Her first postdoctoral position was held at the School of Computer Studies (now the School of Computing) at the University of Leeds. Greenhill worked with Martin Dyer on the analysis of combinatorial Markov chains and related questions in computational complexity. Then she moved back to Australia to take up an Australian Research Council Postdoctoral Fellowship in the Mathematics Department of the University of Melbourne. She worked with Nick Wormald on the study of random regular graphs.