The Old Priorian Rugby Club had a long history throughout the 1970s and 1980s playing Sunday fixtures against other old boys teams. The Old Priorians were well known and feared as a very good team featuring many players who doubled up playing high level Saturday rugby at Richmond, London Irish, Wasps and more.

The club went into decline, however, and the rugby landscape was changed forever by the advent of professionalism during the mid-1990s. During the early 2000s the club primarily focused on the OPA 7s tournament to bring everyone back together and also fielded a strong side in the annual Cronk-Cunis Under 21 tournament.

It seems that Old Priorians were keen to play alongside each other whenever possible and in December 2007 the, then, younger generation came together to organise an U23 match away to Merchant Taylor's Old Boys. The school was on a high during this 2007-08 season with the U15 Daily Mail Cup winners now in Upper 6th and targeting the championship again. With OPs spread across the UK playing their rugby at University or for Ealing, Richmond, Imperial Medicals and more, the re-formation of the club seemed a long way off until Nick Farren (Chairman) and Colin Stokes decided on a stag do that they would take it upon themselves to re-establish the club and by June 2008 the decision was announced with plans for pre-season in place. Greg Knights was appointed as Coach and OPs came back to rugby in their droves.

Too late to join the league structure, the 2008-09 season was spent playing friendlies against much more established clubs culminating in a heart-breaking 16-11 loss to Teddington in the final of the Middlesex Bowl.

2009-10 saw a new coach in Rob Alexander and the team entered the leagues for the first time at Herts-Middlesex 2 (Level 10). It was this season where the OPs first established their rivalry with the Moorgate-based Honorable Artillery Company. The HAC pipped the OPs to the league title with an 8-6 win but both sides were promoted. The highlight for the OPs was victory in the Middlesex Bowl a year on from their final defeat. Victories over London 2 sides Chiswick and London Nigerian secured the tournament win.

2010-11 proved to be a difficult year for the club but one of consolidation and necessary for the future growth in the coming seasons. Rivals HAC were again champions but the injury-stricken OPs failed to secure promotion under Head Coach Pete Fisher. 2011-12 saw a new coach in Anthony Andrews and a new rivalry established with local side Wasps however two last minute defeats against them meant the OPs finished second in the league, however still gaining promotion to the London leagues.

The OPs took to the London leagues like a duck to water and cruised to an unbeaten league win despite a strong challenge from new rivals Twickenham who finished second. The OP 21-19 away victory over Twickenham, having been 19-7 down with 3 minutes remaining, will live long in the memory of the club. Unbeaten in the league the OPs targeted the RFU Senior Vase too, a national competition culminating at Twickenham Stadium. However it wasn't to be with the OPs succumbing to a powerful Maidstone side in the London Semi-Final.

In 2013-14 the OPs rose to the challenge of life in London 2, again fighting it out with Twickenham for the league championship. The OPs served up one of their best ever performances on the 5th April 2014 with a 28-20 away victory against Twickenham to all but tie up the league.

Old Priorians then spent six seasons in the extremely competitive London 1 North, eventually being relegated down to London 2 North West following the curtailed 2019-20 season, highlights including a 53-42 home victory against Colchester in 2018, along with beating Eton Manor and North Walsham in the same season.