The name Old Firm is a collective term for the Glaswegian football clubs, Rangers and Celtic, generally used pejoratively to suggest that they are running the scene, together, against the wishes of the other clubs in Scotland. The term is derived from the profitable nature of contests between the two. These two clubs are easily the most successful in Scotland, having won between them 62 Scottish Cups and 89 League championships (through 2004).

Games between these two biggest clubs in Scotland (and among the biggest in the United Kingdom) are characterised by sectarian posturing on the part of a minority of both Celtic and Rangers supporters, which can and often does spill over into violence.

The two clubs normally compete four times a year in the Scottish Premier League and are frequently drawn against each other in various Cup competitions.

Old Firm plans to join English Premiership

Both Celtic and Rangers have expressed desires to leave the Scottish league and move to the English Premiership, however, this seems to be a one sided affair. Reports have suggested that Premiership clubs voted 20 - 0 last year to reject the admittance of the Old Firm into the Premiership (why would some of the smaller clubs effectively reduce their chances of staying in the league and the bigger clubs reduce their chances of playing in Europe). Add to this the need for both national football associations (SFA & FA) and Europe's governing body (UEFA) to agree to the switch it is unlikely that either Celtic or Rangers will be playing in the Premiership in the forseeable future. The only hope, it appears, is that the broadcasters SKY feel that the Old Firm would improve the premiership and demand change. Their (SKY's) position is strong through the amount of money that clubs receive for television rights. The main reason for the desire of the Old Firm to switch leagues is mainly financial as the lesser Premiership clubs receive much more in television revenue than Rangers and Celtic currently do in the SPL. Both clubs feel that this lack of revenue and competition is holding them back and not allowing them to realise their full potential both financially and on the pitch.