Lommel United traces its roots to the 1920s in the Limburg region of Belgium, when a factory workers' club called Vlug & Vrij Overpelt-Usines was founded and officially registered with the Royal Belgian Football Association in 1927. The club dissolved and reformed multiple times over the following decades, eventually becoming known as Overpelt Fabriek — a name that reflected its deep ties to the local zinc-manufacturing community.
A significant turning point came in 2003, when the neighbouring club KFC Lommel SK collapsed following bankruptcy. Lommel had carried real pedigree: it had reached the 2001 Belgian Cup Final and competed in the UEFA Intertoto Cup in both 1997 and 1998. The two clubs merged to form KVSK United Overpelt-Lommel, inheriting Overpelt's registration number but relocating to the Soevereinstadion in Lommel and blending both clubs' colours — green and white from Lommel, red and blue from Overpelt — into a shared identity.
The merged club quickly found its footing, winning the third division title in an undefeated campaign before competing at the second tier. In 2010, a further merger with KFC Racing Mol-Wezel brought the current name Lommel United into use. The club reached professional football's second level in Belgium, though it was relegated after a difficult 2016–17 season, at which point the name was simplified to Lommel SK.
In May 2020, City Football Group — the Abu Dhabi-backed network also behind Manchester City — acquired the club, making Lommel its ninth member. That affiliation now defines much of the club's modern identity, positioning it as a development and talent-pathway hub within one of football's most prominent multi-club ownership structures.