Le Castellet (; ) is a commune in the Var department of the Provence-Alpes-Côte d'Azur region in Southeastern France. It consists of a small feudal village perched on a cliff edge and its surroundings. It is situated north-west of Toulon next to La Cadière-d'Azur and Le Beausset. It is surrounded by vineyards and is part of the Côtes de Provence Appellation d'origine contrôlée (AOC) of Bandol. It is a member of Les Plus Beaux Villages de France (The Most Beautiful Villages of France) Association. The Circuit Paul Ricard is also located in the commune.
Le Castellet has a hot-summer Mediterranean climate (Köppen climate classification Csa). The average annual temperature in Le Castellet is . The average annual rainfall is with November as the wettest month. The temperatures are highest on average in July, at around , and lowest in January, at around . The highest temperature ever recorded in Le Castellet was on 5 August 2017; the coldest temperature ever recorded was on 7 March 1971.
Le Castellet was the setting for the film The Baker's Wife (French: La femme du boulanger), starring Raimu and directed by Marcel Pagnol.