Knox made his professional debut on 4 March 1994 with a fourth-round
knockout win over Ian Bailie. On 20 November 1995, Knox for Louis Veitch for the vacant
BBBofC Scottish Area
flyweight title, winning via sixth round
technical knockout (TKO). His next fight was on 21 March 1996, against Mickey Cantwell (10-3-1) for the vacant British flyweight title. Knox suffered his first career defeat, losing by a twelve round points decision. On 13 September 1996, Knox challenged undefeated Danish fighter
Jesper Jensen (17-0) for the
EBU European flyweight title, losing by
unanimous decision. Two judges scored the bout 117-112, while the third scored it 117-113. Knox again challenged for the vacant British flyweight title on 27 January 1997, against undefeated
Ady Lewis (11-0), losing again by points decision. His next title attempt came on 1 June 1998, against Zimbabwean
Alfonso Zvenyika Lambarda (10-6), losing by eighth-round TKO. On 22 May 1999, Knox challenged undefeated British and Commonwealth flyweight champion
Damaen Kelly (9-0) at the Maysfield Leisure Centre in
Belfast, Northern Ireland. The fight was stopped after the end of round six due to Kelly suffering cuts above both eyes, crowning Knox the British and Commonwealth flyweight champion via sixth round TKO. Knox defended his titles against
Nottingham fighter
Jason Booth (15-1) on 16 November 1999. Knox lost the fight, and his titles, when the referee waved off the fight in the tenth round after Booth landed a clean right uppercut. On 20 March 2001, Knox fought Colombian
IBO light flyweight champion Jose Garcia Bernal (24-4-1) at the Bellahouston Leisure Centre In
Glasgow, Scotland. Knox lost by split decision (115-114, 113-117, 113-116) in what would be the final fight of his professional career. == Professional boxing record ==