The Eagles were founded in 1978/9 as a junior club known as Westbury United, based on the estate where most players lived. They later changed their name to Letchworth Garden City Eagles and now enter junior teams from u7 to u18 in the Royston Crow Youth League and Mid Herts Minors League.
Since the mid nineties the junior club has rapidly expanded to its present size of around 400 registered players.
In 2006 the club completed new changing and clubroom facilities at its home ground of Pixmore Playing Fields, with the assistance of a grant from the Football Foundation, and facilities have been further improved as the senior teams of the club progress.
In 2008/9 the club entered 2 adult teams in the Herts Senior County League for the first time in order to provide an exit route for its youth players. In 2009/10 the first team won the division 1 title and the Aubrey Cup.
In 2010/11 the team was promoted to the Premier Division of HSCL, and finished runners up behind Hinton after heading the table for most of the season. In that season the team reached the final of the Herts Senior Centenary Trophy, losing 3-2 to London Lions, and were winners of the Anagram Records Trophy. They also won the Aubrey Cup for the second successive season and won the cup for a record third time in 2011/12 season.
In 2010/11 season the reserve team won division 1 of the Reserve Section of the HSCL.
In 2014/2015 the Eagles won the Herts Senior Centenary Trophy by beating Belstone FC 3-2 and went on to win the Anagram Records Trophy. They completed the season as runners up in the HSCL Premier Division.
The club is an FA Charter Standard Development Club and in 2008/9 it achieved the honour of being named as Herts FA Charter Standard Development Club of the year.