The Old Firm is the collective name for the Scottish football clubs Celtic and Rangers, which are both based in Glasgow. The two clubs are the most successful and popular in Scotland, and the rivalry between them has become deeply embedded in Scottish culture. It has reflected and contributed to political, social and religious division and sectarianism in Scotland. As a result, the fixture has had an enduring appeal around the world.
Between them the two clubs have won 108 Scottish League championships (Rangers with 55 and Celtic with 53), 75 Scottish Cups (Celtic with 41 and Rangers with 34), and 48 Scottish League Cups (Rangers with 27 and Celtic with 21). Interruptions to their ascendancy have occurred rarely, mainly in the two decades after the Second World War from 1946 to 1965 when five other clubs all won the senior league, and in the first half of the 1980s with the challenge of the New Firm of Aberdeen and Dundee United. Beginning with the 1985–86 season, one half of the Old Firm has won the Scottish League every season and in all but one of seventeen seasons between 1995–96 and 2011–12, both clubs finished in the top two places. In the early 2010s, Rangers endured financial difficulties, and its holding company was liquidated in 2012. Subsequently, the team had to apply for entry to the bottom (fourth) tier of the Scottish league, climbing to the top division in four seasons and winning the title again in 2020–21 (Celtic were champions in each of the intervening nine campaigns but failed to claim the tenth, which would have beaten a record set by them in the 1960s/70s and matched by Rangers in the 1980s/90s). As a result of these circumstances, a proportion of Celtic supporters maintain that the current Rangers is distinct from the pre-2012 club and the rivalry no longer exists under the Old Firm identity; instead, they (and often Celtic themselves) use the more generic term "Glasgow derby" to refer to the rivalry.
Celtic and Rangers have played each other 436 times in major competitions: Rangers have won 169 matches, Celtic 165 matches, and 102 ended in a draw.