[1] Shelford was a Manukau Magpies junior and played for the club in the Auckland Rugby League competition.
In 1985 he won the Bert Humphries Memorial award as the most improved back in the competition.
[6] Between 1989 and 1991 Shelford was a New Zealand national rugby league team representative, playing in ten Test matches.
Kelly Shelford played loose forward in Warrington's 10-40 defeat by Wigan in the 1994–95 Regal Trophy Final during the 1994–95 season at Alfred McAlpine Stadium, Huddersfield on Saturday 28 January 1995.
[8] After leaving Warrington, Shelford returned home and joined the Waikato Cougars in the National Provincial Competition.