Bas-Sassandra District (; , "Lower Sassandra") is one of fourteen administrative districts of Ivory Coast. The district is located in the southwest part of the country. The capital of the district is San-Pédro.
The district was created in a 2011 administrative reorganisation of the subdivisions of Ivory Coast. Its territory is composed of the former region of Bas-Sassandra with the addition of the department of Fresco, which was transferred from the region of Sud-Bandama.
Bas-Sassandra District is currently subdivided into three regions and the following departments:
According to the 2021 census, Bas-Sassandra District has a population of 2,687,176.