The traditional crossing point between the islands of Benbecula and South Uist in the Outer Hebrides, the South Ford tends now to refer to the entirety of the shallow, broad and sandy channel, littered with islands, islets and rocks, which extends from the low-lying island of Gualan in the west, opening into Bagh nam Faoileann in the east. The width of the channel ranges between a half-mile (0.8 km) and 2 miles (3 km) at its western end.
Travellers could cross between the islands at low tide, but the danger of a rapidly advancing tide and quicksands required considerable caution. The crossing was bridged in 1942 and this was replaced by the South Ford Causeway in 1982.
The much wider North Ford separates Benbecula and North Uist 6 miles (10 km) to the north.