Some of the most exciting developments in geometric representation theory revolve around the relatively new theory of W-algebras. Broadly speaking these are obtained via the process of quantum Hamiltonian reduction from the some of the most influential structures in modern representation theory: enveloping algebras and universal affine vertex algebras. The applications of W-algebras are seemingly endless, but we list some key examples: the ordinary and modular representation theory of Lie algebras, the classification of integrable systems (especially generalisations of the KP hierarchy), a deeper understanding of smooth representations of affine Lie algebras, conformal field theories (and their associated AdS duals), modular tensor categories and the famous geometric Langlands program, once described by Edward Frenkel as “the grand unifying theory of mathematics”. The aim of this workshop is to bring the world's leading experts together to investigate recent developments in the theory of W-algebras and their representation theory, as well as interactions with other topics in geometric representation theory.