Csepel Island (Hungarian: Csepel-sziget, Hungarian pronunciation: [ˈtʃɛpɛl]) is an island in the Danube in Hungary. It is 48 km (30 mi) long; its width after 3 km (2 mi) sections of bifurcation and rejoining (confluence) varies from 6 to 8 km (4 to 5 mi). It has an area of 257 km (99 sq mi) and its population is 165,000.
The isle extends south from Budapest; its northern point or section is Csepel – Budapest's District XXI. Most of the island is accessible from Budapest by the suburban railway. Towns include Ráckeve, Szigetszentmiklós, Szigethalom and Tököl.