Catherine Greenhill is internationally recognised as a leading expert in asymptotic, probabilistic and algorithmic combinatorics, undertaking research at the interface between combinatorics, probability and theoretical computer science. She tackles difficult, fundamental questions about ubiquitous combinatorial objects, such as graphs and hypergraphs. She has achieved major breakthroughs including establishing the efficiency of a natural algorithm for generating graphs, and finding threshold values for the emergence of certain structures in random hypergraphs. Her highly cited research provides new formulae and algorithms that have found broad applications in many areas, including cryptography and physics.