Nick Shepherd-Barron is one of the world’s leading algebraic geometers, and his work has had a major impact on modern work on classification of higher-dimensional varieties. He has provided remarkable solutions to many deep and difficult problems across a broad range of topics in algebraic geometry and related areas of number theory. These include singularities of surfaces and threefolds, invariant theory and rationality of moduli spaces, the integrability of foliations in finite characteristic and its arithmetic applications, the classification of surfaces and Fano threefolds in finite characteristic, and the modularity of representations of Galois groups.