The Cross-Sanaga-Bioko coastal forests are a tropical moist broadleaf forest ecoregion of west-central Africa. This is lush forest rich in flora and birdlife.

The region includes the lowland and coastal forests of southeastern Nigeria, southwestern Cameroon, and the lowlands of the island of Bioko, covering an area of 52,200 square kilometers (20,200 sq mi). The ecoregion extends from the Cross River in southeastern Nigeria to the Sanaga River in southeastern Cameroon, and up to 300 km inland from the Atlantic coast. In Nigeria the region more or less covers Cross River State.

The highlands of Mount Cameroon and of Bioko island, above 900 meters elevation, are a distinct ecoregion, the Mount Cameroon and Bioko montane forests, as are the Cameroonian Highlands forests further inland. To the west, across the Cross River, lies the Cross-Niger transition forests ecoregion. Towards the drier interior, the coastal forests transition to the Guinean forest-savanna mosaic to the north and the Northern Congolian forest-savanna mosaic to the east. South of the Sanaga River along the coast lies the Atlantic Equatorial coastal forests ecoregion.