The union territory of Puducherry consists of four small unconnected districts: Puducherry district (293 km2 (113 sq mi)), Karaikal district (160 km2 (62 sq mi)) and Yanam district (30 km2 (12 sq mi)) on the Bay of Bengal and Mahé district (9 km2 (3.5 sq mi)) on the Arabian Sea, covering a total area of 492 km2 (190 sq mi). Puducherry and Karaikal have the largest areas and population, and are both enclaves of Tamil Nadu. Yanam and Mahé are enclaves of Andhra Pradesh and Kerala, respectively. Its population, as per the 2011 Census, is 1,244,464.

Some of Puducherry's districts are themselves amalgamations of non-contiguous enclaves, often called pockets in India. The Puducherry district is made of 11 such pockets, some of which are very small and entirely surrounded by the territory of Tamil Nadu. Mahé district is made up of three pockets. This unusual geography is a legacy of the colonial period with Puducherry retaining the borders of former French India.

All four districts of Puducherry are located in the coastal region. Five rivers in Puducherry district, seven in Karaikal district, two in Mahé district and one in Yanam district drain into the sea, but none originates within the territory. Districts of Puducherry

1. Puducherry district, an enclave of Tamil Nadu
2. Yanam district, an enclave of Andhra Pradesh
3. Karaikkal district, an enclave of Tamil Nadu
4. Mahé district, an enclave of Kerala