This modern treatment of Poisson geometry fulfills a twofold purpose, offering both a quick, self-contained introduction to Poisson geometry and related subjects, and a comprehensive treatment of the normal form problem in Poisson geometry. Topics covered in detail include singular foliations, Lie groupoids and Lie algebroids. The book includes both new and classic material, offering new insight into results obtained over the past 10 years which are not available in other publications.