[1] In 1921, a Northern section was also created called the Third Division North.
For the 1950–51 season the division was expanded to 24 clubs, with Colchester United and Gillingham joining.
Six teams, Brighton & Hove Albion, Exeter City, Northampton Town, Southend United, Swindon Town, and Watford, were ever-present in the division for the 30 years of its existence.
Of the teams that played in the Third Division South, Portsmouth, Ipswich Town, and Nottingham Forest were later English football champions.
From 1934 to the war's outbreak, there was a short-lived knockout competition Football League Third Division South Cup.