South Fermanagh was a constituency of the Parliament of Northern Ireland.

Fermanagh South was a county constituency comprising the southern part of County Fermanagh.

It was created in 1929 when the House of Commons (Method of Voting and Redistribution of Seats) Act (Northern Ireland) 1929 introduced first-past-the-post elections throughout Northern Ireland.

The constituency survived unchanged, returning one member of Parliament until the Parliament of Northern Ireland was temporarily suspended in 1972, and then formally abolished in 1973.

The seat was consistently won by the Nationalist Party candidate, who, for most of its existence, was the party leader, Cahir Healy.