2012–13 Isthmian League

The 2012–13 season was the 98th season of the Isthmian League, which is an English football competition featuring semi-professional and amateur clubs from London, East and South East England.

The constitution of the three divisions was announced on 25 May 2012. For this season, only two clubs were relegated from the Premier Division, and one from each Division One. This was to allow for expansion to 72 clubs for the 2013–14 season.

Premier Division
The Premier Division consisted of 22 clubs, including 16 clubs from the previous season, and six new clubs:
 * Bognor Regis Town, promoted as play-off winners in Division One South
 * Enfield Town, promoted as play-off winners in Division One North
 * Hampton & Richmond Borough, relegated from the Conference South
 * Leiston, promoted as champions of Division One North
 * Thurrock, relegated from the Conference South
 * Whitehawk, promoted as champions of Division One South

Whitehawk won the division to earn a second consecutive title and were promoted to the Conference South along with play-off winners Concord Rangers. Due to league expansion there were only two relegation places this season. Initially, Carshalton Athletic and Hastings United were relegated, but Thurrock were subsequently deducted three points for fielding a suspended player on the second day of the season. It sent Thurrock bottom of the table and they were relegated for a second consecutive season. A subsequent appeal was rejected. This allowed for an effective reprieve for Carshalton Athletic.

Division One North
Division One North consisted of 22 clubs, including 19 clubs from the previous season, and three new clubs:
 * Aveley, relegated from the Premier Division
 * Witham Town, promoted as champions of the Essex Senior League
 * Wroxham, promoted as champions of the Eastern Counties League

Grays Athletic won the division and were promoted to the Premier Division along with play-off winners Thamesmead Town. Due to league expansion, there was only one relegation place this season. Ilford finished bottom of the table and were relegated from the division after seven seasons.

Division One South
Division One South consisted of 22 clubs, including 17 clubs from the previous season, and five new clubs:
 * Herne Bay, promoted as champions of the Kent League
 * Horsham, relegated from the Premier Division
 * Leatherhead, relegated from the Premier Division
 * Three Bridges, promoted as champions of the Sussex County League
 * Tooting & Mitcham United, relegated from the Premier Division
 * Crawley Down F.C. changed their name to Crawley Down Gatwick F.C.

Dulwich Hamlet won the division and were promoted to the Premier Division along with play-off winners Maidstone United, who returned after two seasons of absence. Due to league expansion, there was only one relegation place this season. Walton Casuals finished bottom of the table, but were reprieved for the second time in four seasons.

League Cup
The Isthmian League Cup 2012–13 was the 39th season of the Isthmian League Cup, the cup competition of the whole Isthmian League.

First round
Four clubs from divisions One participated in the First round, while all other clubs received a bye to the Second round.

Second round
The two clubs to have made it through the First round were entered into the draw with every other Isthmian League club, making sixty-four teams.