Rangers has a long-standing rivalry with Celtic, the two Glasgow clubs being collectively known as the Old Firm, which is considered one of the world's biggest football derbies. With more than 600 Rangers supporters' clubs in 35 countries worldwide, Rangers has one of the largest fanbases in world football.

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 49 Scottish League Cups (Rangers with 28 and Celtic with 21).