The area of Casamance is the part of southwestern Senegal south of The Gambia including the Casamance River.

Low-lying and hot, with some hillss in the southeast, it is a rice-growing area with a tourism trade on its Atlantic Ocean beaches, particularly at Cap Skirring.

The largest town is Ziguinchor. The dominant ethnic group in Casamance is the Jola (Diola), though they are an economically disadvantaged group in Senegal as a whole. This has in part caused a separatist movement for the independence or autonomy of Casamance, that has involved violent confrontations with Senegalese forces and killings for decades towards the end of the 20th century.

Casamance has greater rainfall than the rest of Senegal to the north.