Kelly, the youngest of a family of 13, originally started playing football as a striker, and was reasonably successful in this position for
Home Farm. However, when he joined Leeds, then boss
Howard Wilkinson recognised qualities in him that would make a very good wing-back. Kelly made his debut for Leeds in the
1991–92 season, although he did not become a regular in the side until the
1993–94 season, when Wilkinson made him his first choice right-back following the injury-induced retirement of
Mel Sterland, occasionally filing in at centre back when needed. He had played just twice in the 1991–92 season, when Leeds were champions of the last old
Football League First Division before the
FA Premier League was created, and did not qualify for a title winner's medal. He was selected in the Premier League team of the season for the 1993–94 campaign. By the end of that season, he had also played himself into
Jack Charlton's Republic of Ireland squad that went to the 1994 World Cup in the USA. Kelly was one of the "Three Amigos" alongside
Phil Babb and
Jason McAteer whose youthful exuberance rejuvenated an ageing Irish squad. Kelly scored in a 2–0 victory over Germany in a warm-up friendly before those finals. Kelly was installed by
George Graham as his skipper in the
1997–98 season, at the age of 23. Kelly was generally a regular either at right back or right midfield in every subsequent season he played for Leeds, except for
1998–99, when shin splints ruined his season (this injury would reoccur in subsequent seasons). But Kelly forced his way back into the Leeds first team, in 1999–2000, making the right back role his own, despite the signing of
Danny Mills in the summer of 1999. Kelly once again took over as skipper when
Lucas Radebe was on international duty. He was rewarded with a testimonial match in May 2002, played against
Celtic. The proceeds from this match were donated to several cancer charities chosen by Kelly (mainly Teenage Cancer Charity in
Leeds and Cancer Support Centre in Drogheda), in dedication to his sister, Mandy, who died from the disease in 1998 aged only 35. Seen by a crowd of 26,440, Celtic won this match, which generated nearly £1 million in receipts – making up the majority of the total £1.5 million which was raised to open a cancer centre in his native Drogheda. He is also only the 10th player to ever make over 500 appearances for Leeds United, making the feat against
Luton Town in Leeds' 2–1 victory at
Elland Road on 25 February 2006. Kelly played regularly in the first half of his 16th season at Leeds. But at that stage, he had fallen out with
Ken Bates and new Leeds manager, Dennis Wise. On 26 October 2006,
Wise revealed
Shaun Derry was replacing Kelly as the new Leeds vice captain. After 16 years of loyal service to the club, a presentation of a crystal cut vase was made to Kelly at the last home game of the 2006–07 season by former Leeds United players
Paul Reaney,
Allan Clarke,
Mick Jones, and
Frank Worthington. ==International career==