The club was founded in 1896 and was initially known as Horwich RMI, the club's name until 1995 when it relocated to Leigh and was renamed Leigh RMI. It's name was changed again in June 2008 when the club became Leigh Genesis FC.

RMI were one of two football clubs founded at the locomotive-building works of the Lancashire and Yorkshire Railway; it was started at the main works in Horwich. The other club was started at the Newton Heath works and later became known, and famous, as Manchester United. RMI played in various non-professional conferences over its first 90 years of existence, primarily in the Lancashire Combination, before moving into the newly formed North West Counties League in 1982 and then onto the Northern Premier League the next year.

Manager Les Rigby led RMI to the final of the GMAC Cup in 1988 against Weymouth, which was played on the sloping pitch of Grundy Hill. The home advantage was credited by many, including Rigby, for spurring RMI's victory in the match.

During the 1994-1995 season, the club realised their ground Grundy Hill would not be able to help the club's prospects of achieving success further up the football pyramid and made the decision to move seven miles south from Horwich to Hilton Park in Leigh, home of the rugby league club Leigh Centurions. As part of this deal, a new company, Grundy Hill Estates, was formed to take over the ownership of the shared ground. Once the move had been finalised and agreements had been made to share the 10,000 capacity stadium, the club officially changed their name to Leigh RMI to reflect their new surroundings. RMI lost its first match at Hilton Park in March 1995 to Boston United 4-0, and ended up being relegated from the Northern Premier League at the end of the 1994/1995 season.