Tony Spearing is a product of the Norwich City youth side that won the FA Youth Cup in 1983. As a left back, his opportunities to play for the first team were limited by the presence of Greg Downs and Paul Haylock. His first team debut came in May 1984 in a meaningless end of season clash away to Tottenham Hotspur. A broken leg on his fourth senior appearance at the beginning of the next season ruled him out of contention for a long period of time. He fought back from this injury and gained valuable experience on loan to Stoke City and Oxford United. Eventually he established himself again in the Norwich first team squad and by the time of his eventual departure to Leicester City in July 1988, Tony had made 82 first team appearances.

He cost Leicester £100,000 and in the next three seasons, he made 73 appearances scoring his first league goal against Newcastle. Under Brian Little's managerial regime, Tony did not fit in and so transferred to Plymouth in July 1991. 35 games for the Devon side was followed by a transfer to Peterborough where he was a regular in their defence. The 1996/97 season brought him up to a grand total of 111 league appearances for the Posh with two goals to his credit. He was part of Barry Fry's summer 97 clearout that saw Tony join Norfolk's leading non-league side King's Lynn on a free transfer whilst former Canaries Louie Donowa and Jon Sheffield joined Walsall and Plymouth respectively.

Tony has proved himself popular with the Linnets' fans and became the new manager of Lynn following Peter Morris' departure to Kettering in May 1998. He suffered a baptism of fire as a new look King's Lynn side endured a number of defeats at the start of the 1998/99 season. In late September, he decided that he was not suitable to be Lynn's manager and resigned, returning to being solely a player. His replacement was former Nottingham Forest player Gary Mills. The tables were turned in November 2000 when Mills' resignation resulted in Spearing taking temporary charge. Lynn's success under Spearing's leadership despite financial difficulties saw him appointed to the substantive post, bringing in Tommy Wright and Darren Bloodworth as assistants.

Spearing's four and a half year reign at The Walks ended on 1st March 2002 when the club's board "relieved him of his duties as manager" following a review of the club's position. Since his departure, he initially helped out old friend Henry Nicholson by playing for Stalham's defence but signed up for AFC Sudbury. In his first full season with the Suffolk side, Spearing and Sudbury went on to win the Jewson League and reach the final of the FA Vase. Unfortunately they lost the latter 2-1 to Brigg Town on May 10th 2003. However this was to be Spearing's final appearance for Sudbury as new manager Gary Harvey opted not to re-sign him for the new campaign along with Wayne Anderson and Ross Taylor. They have been partly replaced by new signings Simon Head (Halstead) and Neil Calver (Woodbridge).

After training with Wroxham and Great Yarmouth in the summer of 2003 to keep fit and appearing for them in pre-season friendlies, he signed for the Bloaters as a player with the plan to help develop the younger players at the club. In the summer of 2004, he left Yarmouth despite playing for them against Norwich City. After a couple of friendlies with Norwich United, he joined Wisbech Town making his debut for the fenmen against Leiston on 21st August 2004. He parted company with the Fenmen over the weekend of 9th October 2004.

In the summer of 2005, Tony helped with the coaching at cash struck Cambridge United and Rob Newman then appointed Spearing as his assistant manager. Spearing signed a new contract with Cambridge on 8th April 2006 as did Newman. However after a poor start to the 2006/7 season saw them at the bottom of the Conference following a defeat at Exeter on 1st September 2006, Newman and Spearing were sacked with new chairman Lee Power temporarily taking over team selection

Spearing was appointed Senior Scout at Blackburn Rovers but in March 2008, left Blackburn to take up an offer from West Bromwich Albion to become the Head of European recruitment.