Colin Calderwood became Norwich's Assistant Manager on 7th June 2012 when he followed Chris Hughton from Birmingham to Norwich.

A centre-half, Calderwood began his career at Mansfield, making 100 appearances before joining Swindon for a tribunal set fee of £27,500 in 1985. He made 330 league appearances for Swindon, during which time the club was promoted from Division Four to the Premier League

When his contract expired in 1993, he joined Tottenham and made 162 league appearances for them. He was also capped by Scotland on 36 ocassions. In 1999, he joined Aston Villa (26 appearances) before ending his career with brief spells at Notts Forest and Notts County. He retired in 2001.

He became reserve team manager at Spurs before being appointed manager of Northampton in October 2003. They won promotion from League Two in 2006 which led to Calderwood becoming Notts Forest manager. Although he won promotion to the Championship in May 2008, he was sacked the following October. He then joined Newcastle as first team coach and was assistant to Hughton on Tyneside.

In October 2010, he joined Hibs as manager but was sacked in November 2011. He joined Hughton at Birmingham later that month.

Hughton, Calderwood and Paul Trollope helped Norwich to 11th place in their first season in charge but dismal form in their second saw them sacked on 6th April 2014, with the board explaining: “Norwich City can confirm Chris Hughton, Colin Calderwood and Paul Trollope have parted company with the club with immediate effect - and former Canary winger and FA Youth Cup-winning coach Neil Adams has been appointed as first team manager. The Norwich City board has taken the decision to give the club the maximum chance to secure the points required between now and the end of the season to ensure retention of our Premier League status. the club would like to place on record it’s sincere thanks to Chris Hughton, Colin Calderwood and Paul Trollope for all of their hard work on behalf of the club since they took over in June 2012. Chris’s achievement in guiding City to an 11th-place finish in the Premier League last season was an excellent one and he has represented the club with dignity throughout his tenure. However the recent run of four defeats in our last six Premier League games and six consecutive away league defeats, left the club with no choice but to act, with five games still to play in the current campaign.”

Calderwood teamed up with Hughton again in February 2015 when he became Hughton's assistant at Brighton on 3rd February 2015. "I know him well and we wanted to bring someone in of Colin's experience," Hughton told the club website. "I know that he will work well with the existing coaching staff at the club and I think he'll be a very good addition."

On 12th November 2016, Calderwood resigned from the job at Brighton and six days later it was confirmed that he had joined Steve Bruce at Aston Villa where he would be Assistant Manager. Calderwood left Villa on 3rd October 2018 after the dismissal of Bruce.

On 19th December 2018 he was named the new manager of Cambridge United replacing Joe Dunne who was sacked on 1st December. "Colin brings a wealth of experience and a track record of success as a player, manager and coach," said Cambridge director of football Graham Daniels.

He was sacked as Cambridge manager on 29th January 2020 following a run of five games without a win that saw them slip to 18th place in League Two.

Despite reports linking him with Notts Forest and working again with Chris Hughton, Calderwood instead agreed to become the first head coach of Northampton Town's International Football Academy which will open in January 2021. He then joined Blackpool as Assistant Manager in October 2020. He left in June 2021 and became Assistant Manager at Northampton on 17th June 2021.

He left his role at Northampton on 30th October 2023 to become first team coach at Southampton managed by Russell Martin.