The South Fork Coquille River is the longest tributary of the Coquille River in coastal Oregon in the United States. From its headwaters in the Southern Oregon Coast Range, the river flows northwest to join the North Fork Coquille River at Myrtle Point, forming the main stem Coquille. The South Fork is about 63 miles (101 km) long, and its watershed drains roughly 288 square miles (750 km2) of rural Coos County.

The Coquille River is a stream, about 36 miles (58 km) long, in southwestern Oregon in the United States. It drains a mountainous area of 1,059 square miles (2,740 km2) of the Southern Oregon Coast Range into the Pacific Ocean. Its watershed is between that of the Coos River to the north and the Rogue River to the south.