The club was founded in 1948 after an inaugural meeting chaired by the then Headmaster of Launceston College, Mr Spencer Toy with Gordon Reeve, Eric Smith and Arthur Venning (who is still a member). By Spring 1949, the club had its own ground, rented from the council (now a factory site of its main sponsor DS Smith Plc), with scaffolding poles for goal posts and ex-army huts for changing rooms and a clubhouse. The club moved to another site when the Town Council sold the land, but again moved on in 1969 when the club had the vision to refuse becoming part of the proposed Sports Centre. The ground at Polson Bridge was purchased in 1969, with developments such as floodlights, enlarged clubhouse, present changing rooms and finally the grandstand being added over the years.
In 1981 they then went on to win the Cornwall Senior Cup for the first of many since wins and started their remarkable climb to be one of the top 40 sides in England (from a town with a population of just over 7,000). LRFC gained promotion to National League Division 3 South (level 4) in 2000 and were runner-up in their first season, losing in the play-off away to National 3 North side Sedgley Park. The following season, 2001–02, LRFC were 2nd again, but this time won the play-off against Dudley Kingswinford, and were promoted to Division Two (level 3). They were unfortunate to be relegated after a most unusual series of results on the last day of the season. However, in 2003–04 Launceston bounced right back by again finishing second but winning the play-off away to Halifax. LRFC finished in 5th position in National League Division 2 (level 3) in 2004–05 and by the end of the 2006–07 season they had been promoted to English National Division 1 (level 2). On 26 April 2008, the Cornish All Blacks suffered a final day relegation to Division 2 (level 3) as an unexpected sequence of final day results saw relegation threatened Birmingham & Solihull and Sedgley Park pull off dramatic wins against Bedford and Rotherham respectively. The Cornish All Blacks were relegated when they had actually won more games than either of their two rivals. In truth the damage had been done earlier in the season when losses against Newbury (away), Nottingham (away), Sedgley Park (away), Birmingham & Solihull (away), Esher (home) came back to haunt the coaching staff and players.
2008–09: finished 7th in National League 1 (level 3)
2009–10: finished 3rd in National League 1 (level 3). Equivalent to 27th best club in the country. The highest result achieved by the Cornish All Blacks.
2010–11: Launceston Rugby Football Club Ltd went into administration. A new company Launceston Rugby Club Ltd was formed. The RFU gave the Cornish All Blacks a 20-point deduction. The Cornish All Blacks won only 10 of 30 games for a points total of 44 after the 20 point deduction. Ironically 64 points was the minimum to prevent relegation. The Cornish All Blacks were relegated along with Redruth and Otley.
2011–12: finished 7th in National 2 South (level 4) winning 16 of 30 games
2012–13: finished 7th in National 2 South (level 4) winning 14 of 28 games
2013–14: finished 12th in National 2 South (level 4) winning 15 of 30 games
2014–15: finished 10th in National 2 South (level 4) winning 12 of 30 games
2015–16: finished 16th in National 2 South (level 4) winning 0 of 30 games (relegated)
2016-17: finished 12th in National 3 South West (level 5) winning 7 of 26 games (relegated)