Welington Celso de Melo (17 November 1946 – 21 December 2016) was a Brazilian mathematician. Known for his contributions to dynamical systems theory, he served as full professor at Instituto Nacional de Matemática Pura e Aplicada from 1980 to 2016. Melo wrote numerous papers, one being a complete description of the topological behavior of 1-dimensional real dynamical systems (co-authored with Marco Martens and Sebastian van Strien).He proved the global hyperbolicity of renormalization for Cr unimodal maps (co-authored with Alberto Pinto and Edson de Faria). He was a recipient of the 2003 TWAS Prize.