The South Londonderry constituency for the Parliament of Northern Ireland was created in 1929 and continued until the abolition of the Parliament in 1973.

All members for the constituency were from the Chichester-Clark family: the first was both the son-in-law of the second and the father of the third.

Her grandson James Dawson Chichester-Clark was Prime Minister of Northern Ireland from 1969–1971 and after his resignation was created Baron Moyola in 1971.

All three elected members were not only from the same party, but were close relations, as were the penultimate member of the South Londonderry constituency for the Westminster parliament in 1922 and the Westminster MP for Londonderry from 1955 to 1972.

The elections in this constituency took place using the first past the post electoral system.