Tony Warner began his playing career at Liverpool where he did not make a first team appearance even though he was on the subs' bench numerous times. He played on trial for Ipswich in October 1998 in Tony English's testimonial against Colchester. After loan spells with Swindon, Celtic and Aberdeen, he joined Millwall in 1999. Making 200 appearances for the Lions over a five year period, he was named Millwall's player of the year in 2002/3

He joined Cardiff in July 2004 and made 26 appearances for the Welsh side before joining Fulham, initially on loan.

In August 2006, he joined Leeds on loan, making his debut in place of the injured Neil Sullivan in the 1-0 home victory over Norwich on 5th August 2006. This loan was extended until January 2007 and Warner was a first team regular under Kevin Blackwell but he lost favour under Blackwell's replacement Dennis Wise.

After returning to Fulham on 1st January 2006, he was loaned to Norwich on 2nd March 2007 as a replacement for the injured David Marshall. He made his debut the following day in the 3-1 win at Barnsley. Following the dervy clash with Ipswich on 22nd April 2007, Warner expressed his interest in prolonging his stay at Carrow Road. “I've not spoken to the manager here yet, but I'd like to stay if there was a possibility. This is a great club. You only have to look at the set-up and the manager is working to get them into the Premiership. I've not had a chat with anyone at Fulham yet. I popped back just after Chris Coleman left, but I guess it will be the summer before I get the time to do it.” Tony finished the season with 13 appearances for the Canaries.

On 31st January 2008, Tony joind Barnsley on loan. He made three appearances for them, conceding eight goals in two defeats and one victory. He was released by Fulham in May 2008. On 16th July 2008, Tony signed for Premiership newboys Hull City on a two year deal

On 13th March 2009, Tony was loaned to Leicester City after an injury to David Stockdale. He made his debut in the 1-0 win over Millwall the following day. Leicester went on to win the League One title with Warner playing a total of 4 games.

Tony left Hull by mutual consent on 1st February 2010. Warner signed a two-month contract with Charlton in March following injury to then first choice Rob Elliott. He was named among the substitutes on five occasions but never made his starting debut, and was released at the end of the 2009/10 season

Warner joined Scunthorpe on a one month deal on 22nd October 2010. He made his debut the following day, keeping a clean sheet as Scunthorpe won 2-0 at Watford

Released after a month by Scunthorpe, Warner joined Tranmere Rovers on 7th January 2011 until the end of the season, making his debut the following day in a 3-3 draw with Walsall

Leaving Tranmere at the end of the 2010/11 season despite making 25 appearances, he was linked with Blackburn but Warner's next club was New Zealand's Wellington Phoenix whom he joined on 17th August 2011. They compete in Australia's A-League. He was released at the end of his first season with the Phoenix and returned to England looking for a new club. He trialled with Accrington Stanley, Preston and Southend during the summer of 2012.

In October 2012, Tony was linked with a move to Maltese side Floriana, who were also hoping to aquire former Everton and Arsenal striker Francis Jeffers. Warner's move materialised on 11th October 2012, with Jeffers signing the following day.

In the summer of 2013, Warner joined Blackpool as their player / goalkeeping coach. He was released at the end of the 2013/14 season having not played for the Seasiders.

He signed a short term deal with Accrington Stanley on 26th March 2015 despite being on the coaching staff at Bolton. He was released by Stanley in May 2015.

On 2nd July 2015, he joined Indian Super League side North East United as goalkeeping coach but this was terminated on 2nd August 2015 when he applied for the main golakeeping coach position at Bolton.

In the summer of 2017, Warner became the goalkeeping coach at Indian Super League side Chennaiyin who are managed by former Aston Villa manager John Gregory. Former Huddersfield player Mark Lillis is Assistant Coach. Chennaiyin were Indian Super League champions in 2016 under Marco Matterazi's management. They won the Indian Super League in 2018 by beating Bengaluru FC 3-2 in the final.

On 26th July 2018 he returned to England joining Accrington Stanley as goalkeeper coach. He was also registered as a player, taking the squad number 34 and being named on the substitutes' bench for the first match of the 2018-19 season at home to Gillingham. He didn't play competitively for Stanley.

In July 2021 he joined Bristol Rovers as their goalkeeping coach.

On 21st June 2022 he left Rovers to become first team goalkeeping coach at Reading.

Tony has one cap for Trinidad & Tobago, awarded in March 2006 against Iceland