Born in Kettering, Northamptonshire, Chambers made his debut for local side Northampton Town against Mansfield in 2003. He was named captain by then Northampton manager Colin Calderwood, who later signed him for Nottingham Forest. His only goal as a Northampton player came against Swansea City in October 2006.
Chambers signed for Forest for an undisclosed fee on 30 January 2007, rejoining former Northampton manager Calderwood. His league debut came away against Bradford City. In his first season, he was mainly used as a substitute. During the 2007–08 season, Chambers was played regularly at right-back as part of a Forest defence that kept a record 24 clean sheets, eventually earning them promotion to the Championship. He scored eight goals in total, six of them in the league.
On 4 August 2008, Chambers signed a new three-year contract, keeping him at the City Ground until 2011. He began the 2008–09 season again selected at right-back. Criticism was expressed at his ability to fulfill that position at Championship level. It wasn't until the arrival of new manager Billy Davies in January 2009 that Chambers was finally selected at centre-back. In the 2008–09 season he scored two goals: the first was the decider in a 2–1 home win against Sheffield Wednesday and the second came on the last game of the season in a 3–1 home win against relegated Southampton.
Chambers started the 2009–10 season as he had ended the last and scoring two goals in the process. This was not enough to keep him in the team however, and the return of Kelvin Wilson from injury, combined with the presence of Chris Gunter at right-back, saw Chambers end the season with a limited number of appearances.
At the start of the 2010–11 season, Chambers signed a new two-year contract to keep him at the club until 2012. Chambers started the 2010–11 season mainly as a substitute, however due to injuries and the poor form of Kelvin Wilson, he was given an opportunity at centre-back. On 18 December, Chambers scored his first goal of the season in a 3–0 home win against Crystal Palace. He impressed with consistent performances, keeping Wilson out of the first team and becoming a first choice (alongside Wes Morgan) in the centre of Forest's defence. He made 45 league starts, scoring 6 goals including two in the 5–1 win over Scunthorpe United. He was voted Player of the Year for the 2010–11 season.
Chambers' form in the 2010–11 season resulted in interest from the Republic of Ireland national team that Chambers qualifies for through his grandfather. On 5 August 2011, just before the start of the 2011–12 season, he was appointed as Nottingham Forest captain by new manager Steve McClaren, and continued to skipper the side under the leadership of McClaren's replacement Steve Cotterill. However, at the end of a difficult season for Forest, he turned down the offer of a new contract, and at midnight on 30 June 2012 Chambers became a free agent.
With his contract at Forest set to expire, Chambers was approached by several other Championship sides, before undertaking a medical at Portman Road on 3 July 2012. Chambers signed a three-year deal at Ipswich Town on a free transfer on 9 July 2012. He made his debut on 14 August 2012, in a 3–1 home win against Bristol Rovers in the League Cup. He made his league debut four days later, in a 1–1 draw at home to Blackburn Rovers. On 1 September, he scored his first goal for the club in a 2–2 draw at home to Huddersfield Town. He also captained the club for the first time during the game due to the absence of regular captain Carlos Edwards through injury. Playing as a central defender, Chambers was part of an Ipswich defence that kept 12 clean sheets in the last 22 games of the 2012–13 season, but early in the following season he was installed at right-back.
Chambers was named club Captain following Edwards' departure in the summer of 2014.
Chambers is an Irish citizen, qualifying through his grandfather. He has yet to receive a call up to the Republic of Ireland squad.As of 31st May 2017
Northampton Town:Football League Two runner-up (1): 2005–06
Nottingham Forest:Football League One runner-up (1): 2007–08
Individual:Nottingham Forest Player of the Year (1): 2010–11