Mathilde Warnier (born October 2, 1991, in Rosny-sous-Bois) is a French actress and model. She first drew public attention in 2011 after appearing on the television show Au Field de la nuit, and then moved into modeling and acting.

In film, she appeared in such feature films as Emmanuel Mouret's Caprice (2015), Bertrand Mandico's Les Garçons sauvages (2017), Curiosa (2019), and Cédric Klapisch's Rise (En corps, 2022). On television, she gained recognition for her role as Sophie Méricourt in the satirical series A Very Secret Service (Au service de la France, 2015–2018). Since then she has expanded her career internationally, in particular by playing Nadine Gires in the British drama series The Serpent (2021), as well as appearing in the series The New Look and It's Not a Murder Mystery.