Sant Carles de la Ràpita is a municipality in the comarca of the Montsià in Catalonia, Spain.

The municipality covers a portion of the south-west of the Ebre delta, including el Trabucador isthmus and la Banya peninsula, which close off a salt water lagoon known as the Port dels Alfacs.

The town of Sant Carles de la Ràpita is situated on the coast near the mouth of the lagoon. It was founded by King Carlos III as a port to serve trade with the colonies, and constructed in the neoclassical style of the period: however much of the town remained incompleted after Carlos’ death.

It is known for the production of rice and salt, and is also an important fishing port, particularly for shellfish and shrimps, and a tourist centre.