2000–01 Isthmian League

The 2000–01 season was the 86th 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 league consisted of four divisions.

Premier Division
The Premier Division consisted of 22 clubs, including 18 clubs from the previous season and four new clubs:
 * Croydon, promoted as champions of Division One
 * Grays Athletic, promoted as runners-up in Division One
 * Maidenhead United, promoted as third in Division One
 * Sutton United, relegated from the Football Conference

Farnborough Town won the division and returned to the Football Conference after two seasons spent in Isthmian League. Slough Town, Carshalton Athletic and Dulwich Hamlet finished bottom of the table and relegated to Division One. Three fixtures left unfulfilled due to bad weather conditions.

Division One
Division One consisted of 22 clubs, including 17 clubs from the previous season and five new clubs: Three clubs relegated from the Premier Division:
 * Aylesbury United
 * Boreham Wood
 * Walton & Hersham

Two clubs promoted from Division Two:
 * Ford United
 * Northwood

Initially, champions of Division Two Hemel Hempstead Town were to be promoted to Division One, but later they were refused due to ground grading. Leatherhead finished in the relegation zone were reprieved.

Boreham Wood won the division and returned to the Premier Division at the first attempt. Bedford Town and Braintree Town also get a promotion. Leatherhead finished in the relegation zone the second time in a row and were relegated along with Romford and Barton Rovers.

Division Two
Division Two consisted of 22 clubs, including 17 clubs from the previous season and five new teams:

Two clubs relegated from Division One:
 * Chertsey Town
 * Leyton Pennant

Three clubs promoted from Division Three:
 * East Thurrock United
 * Great Wakering Rovers
 * Tilbury

Initially, previous season champions of Division Two Hemel Hempstead Town were to be promoted to Division One, but later they were refused due to ground grading and stayed in the division.

Tooting & Mitcham United won the division and were promoted to Division One along with Windsor & Eton and Barking. Later, Barking ceased to exist when they merged with East Ham United (11° Essex Senior League) to form Barking & East Ham United, taken place of Barking in Division One.

Division Three
Division Three consisted of 22 clubs, including 17 clubs from the previous season and five new teams:
 * Arlesey Town, promoted as champions of the Spartan South Midlands League
 * Ashford Town, promoted as champions of the Combined Counties League
 * Chalfont St Peter, relegated from Division Two
 * Wingate & Finchley, relegated from Division Two
 * Witham Town, relegated from Division Two

Arlesey Town and Ashford Town both debuted in the league and achieved a promotion along with Lewes. Two fixtures left unfulfilled due to bad weather conditions.