The club established in 1984 by John Mallon and Johnny Bates (RIP) with the help of local resident and Shamrock Rovers captain Pat Byrne. An U10 and U13 team were entered into the 84-85 South Dublin Boys Football Association with a new home pitch formed in Delaford Park. Pat Byrne arranged donation of two kits from Shamrock Rovers which gave the club their famous green and white hoops. The first committee was established in 1988 headed by first ever Chairperson, John Doyle (RIP).

Since those early days, the club has grown from strength to strength and currently has teams in the DDSL, LFL and LSL with nearly 600 players spread across a variety of sections with 85 girls now playing and 48 Football for All players as well as schoolboy and senior teams. The club also has a thriving academy for 5- and 6-year-old boys and girls where they can benefit from the expertise of the coaching staff, many of whom are ex-players. A hive of activity now centres around the main clubhouse at Ballycullen Park as well as pitches at Delaford, Kennedy Park and Tymon Park.

There have been many success stories through the years. One particular standout season was 1993-94 when the club had 9 league wins, 4 cup wins and 4 runners up finishes. The club has also been represented by players in the famous Kennedy Cup squad. Dundalk stars Brian Gartland and Dane Massey both started their footballing careers at Knocklyon United and more recently,former Knocklyon player, Andrew Moran , now signed to Brighton and Hove Albion, captained the Republic of Ireland’s U15s.

More recently, the club have committed to the provision of  girl’s football and are proud to have a girl’s only academy as well as representation in the U13-U10 girl’s leagues with plans afoot to have U9s and U8s in September.

Knocklyon United are especially proud of the Football for All programme started by Mick Kennedy (former Vice Chair of DDSL) who has opened the pathway for access to football for all players, and offering inclusion for all.

Off the pitch, Knocklyon United has always been a community club and have been supported by and has contributed to, the wider Knocklyon community.

Knocklyon Men’s Shed have the use of the clubhouse as does Ballycullen food bank appeal. Also at the heart of the club are the 84 volunteers who, from the Chairperson and Executive Committee ,through to the Transition Year local students who help at academy, are the force without whom, the club would be lost.