Sophia Maria (Fiep) Westendorp (Zaltbommel, 17 December 1916 – Amsterdam, 3 February 2004) was a Dutch draughtswoman and illustrator. She gained widespread fame with her illustrations for the Jip and Janneke stories by Annie M.G. Schmidt. In addition, she worked for Het Parool and illustrated works by, among others, Mies Bouhuys and Han G. Hoekstra.