Kerr began his professional career at Aston Villa in May 1982 after two years as an apprentice. Villa recorded a sixth-place finish in the First Division in 1982–83 under Tony Barton's stewardship. Following tenth-place finishes in 1983–84 and 1984–85, Villa dropped to 16th in 1985–86. They were then relegated in 1986–87 under Billy McNeill, though Kerr escaped this fate as he left the club in January. Kerr played 34 league and cup games in his five years with the "Villans", scoring six goals. He signed with Middlesbrough in January 1987, and helped Bruce Rioch's side to win promotion at the end of the season after a second-place finish in the Third Division. "Boro" missed out on a second-place finish in 1987–88, as they finished behind Kerr's former club Aston Villa on goals scored. He featured in both legs of the Second Division play-off Final victory over Chelsea. However they were immediately relegated in 1988–89, finishing in 18th place, one point behind Villa. They avoided a second successive relegation in 1989–90, finishing one place and two points above the drop. Kerr also managed to get some revenge over Aston Villa by scoring past them in the 1990 Full Members Cup semi-final, which helped Middlesbrough reach Wembleyfor the first time in the club's history. He was a substitute in the final, as "Boro" lost 1–0 to Chelsea following a first half strike from Tony Dorigo. "Boro" pushed for promotion in 1990–91 under Colin Todd, though Kerr departed Ayresome Park in March having scored 18 goals for Middlesbrough in 162 appearances in all competitions. In March 1991, he was signed by Bruce Rioch for a second time, who was then in charge at Millwall. The "Lions" went on to finish the season in the play-off places, only to lose to Brighton & Hove Albion at the semi-final stage. He then scored twelve goals in 1991–92 to become the club's top scorer during an otherwise disappointing campaign. Kerr scored a total of 15 goals in 51 league and cup appearances at The Den. He signed for Port Vale in July 1992, with manager John Rudge paying a fee of £140,000. He scored 15 goals in 51 appearances in 1992–93, including a goal in the Potteries derby defeat at the Victoria Ground on 24 October. His most crucial goal though came in the fourth minute of the Football League Trophy final, when he converted a Bernie Slaven cross to give the "Valiants" the first goal of a 2–1 win over Stockport County at Wembley. He went on to say: "My goal was a great ball from Bernie. I’d found myself in space behind the defence and seeing the gap between the goalkeeper and the right hand post I decided to take the shot then. I knew there was a defender behind me, but I was just delighted to see the ball hit the back of the net." Eight days later he played in the play-off Final defeat to West Bromwich Albion. Promotion to the First Division was finally achieved with a second-place finish in 1993–94, during which Keer struck five times. Kerr joined Leicester City on loan in March 1994, and scored twice in seven First Division games for Brian Little's "Foxes", before returning to Vale Park at the end of the season. He was released by Port Vale, having scored 20 goals in 84 appearances. He joined Martin O'Neill's Wycombe Wanderers for the 1994–95 campaign, and scored one goal in his only substitute appearance in the league; he also started one cup game for the club.
