[4] Pennant Football Club was formed as a junior side in 1959 by William Bode, initially joining the South West Essex League.

1990–91 saw Walthamstow Pennant win the Spartan League title by a single point from Barkingside with a 4–0 defeat of Thamesmead Town in their final game.

By 1999–2000 the club was struggling on and off the pitch, resulting in a very poor run of form and relegation to the Isthmian League Second Division.

2000–01 saw great inconsistency in results, accompanied by one of the poorest disciplinary records in the whole of English football and the club were called before the FA to explain themselves.

However, results were shambolic and after 4 heavy defeats in their first 4 games Terry Back acted and dismissed both Muir and Fitch.

Honeyball, along with assistant boss Victor Renner rebuilt the side quickly and after an outstanding run of form, finished 8th and just missed out on the end of season play-offs.

Boxing promoter Azumah Cofie took over as chairman; however, the club continued to suffer financial difficulties, and worse was to follow.

It was eventually announced on 14 March 2008 that the club would leave their home of 12 years, Wadham Lodge, at the end of the season.

However, an increase in the rent saw the club move out early, playing their final home game at the Lodge on 24 March 2008, a 1–0 home defeat to Ilford, which put the Stags back in the relegation mire; however, the team eventually secured survival in the penultimate game, a 3–0 victory at Enfield Town.

At the beginning of 2009 Chairman Azumah Cofie handed the reins to local businessman and friend Isaac Johnson, who immediately appointed Olawale Ojelabi as player-manager.

This led to a superb run of form from January to March, which dragged the club out of the relegation places and again Forest survived the drop.

Mercer was dismissed halfway through the 10–11 season with Ojelabi returning as manager but this was not enough as the side finished 21st out of 22 teams but they were reprieved from relegation.

Walthamstow were transferred back to the Isthmian League North Division for the 2023–24 season, the club's first appearance since their relegation in 2014.