Calum Davenport joined Norwich on loan from Tottenham Hotspur on 13th September 2005. The 22 year old central defender joined the Canaries for three months after failing to break into the Spurs first team. He began his career at Coventry, debuting at the age of 18, and winning England Under-21 caps. He made 84 appearances for the Sky Blues before Tottenham paid an undisclosed fee for him in the autumn of 2004. He spent parts of last season on loan to West Ham and Southampton. He made his debut in the 2-1 defeat at Watford on the 13th September.

Calum returned to White Hart Lane in mid-December but with Norwich manager Nigel Worthington keen to bring him back to Carrow Road either permanently or on another loan. On 1st January 2006, Calum was linked in The People with a £800,000 switch to Reading. On 17th January 2006, he was linked with a £1million move to Sheffield United. The League Paper then reported on 19th March 2006 that Davenport and Coventry's Gary McSheffrey topped Reading's transfer targets if they were to win promotion to the Premiership. On 9th April 2006, the News of the World suggested that Davenport was a target for Celtic manager Gordon Strachan who had worked with him at Coventry.

On 31st May 2006, Spurs announced that they would be seeking to sell Davenport, and it is expected that they would seek a fee of around £1million for him. Both the News of the World and The People reported that Watford manager Adrian Boothroyd would be seeking to bring Davenport to Vicarage Road for the Hornets' Premiership campaign.

On 16th June 2006, the Star and the Express both reported that Wolves and Birmingham were locked in a transfer tug-of-war over Spurs £1.5m-rated centre-back Calum Davenport although the Daily Mail speculated two days previously that Celtic and Charlton were also competing with Birmingham for Davenport. On 30th June 2006, The Sun reported that West Brom had made a £1.3m bid for Davenport. The same paper speculated in December 2006 that Davenport would be a makeweight in the transfer to West Brom defender Curtis Davis to Spurs for £5m. The Guardian speculated on 5th January 2007 that Davenport and teammate Wayne Routledge would be offered to Watford in return for highly rated Ashley Young.

On 18th January2007, Calum signed for West Ham United who were spending their new Icelandic owners' money in an attempt to avoid relegation. Other Janaury 2007 signings include Luis Boa Morte (Fulham), Nigel Quashie (West Brom), Lucas Neill (Blackburn) and Matthew Upson (Birmingham)

Reports in July/August 2007 suggested that Davenport might be rejoining City either on loan or as a permanent transfer with the Canaries needing another central defender for the new season. The 24-year-old is likely to be on the sidelines at Upton Park this season, where manager Alan Curbishley has half a dozen central defenders to choose from. He was linked on 12th August 2007 with a switch to Ipswich by the Sunday People but any move to East Anglia was dismissed by his agent two days later.

Davenport joined Watford on 18 January on loan from West Ham United with view to a permanent deal. He had made just 6 appearances for the Hammers since signing for them from Tottenham exactly one year previously. Davenport made his debut for the Hornets on 19 January in a 1-1 draw at home to Charlton but was stretchered off after fracturing a bone in his neck when teammate Darius Henderson landed on him. His injury meant that the loan was cancelled.

Returning to fitness, Calum was linked in January 2009 with a £3million transfer to Gary Megson's Bolton. On 2nd February 2009, just before the end of the transfer deadline day, Davenport signed on loan for Sunderland until the end of the 2008/9 season becoming manager Ricky Sbragia's second signing during the transfer window. He follows Tal Ben Haim's loan switch from Manchester City. Davenport had made just eight appearances forWest Ham during 2008/9 and 14 in total during his two years at the club.

In the early hours of 22 August 2009, Davenport and his mother were stabbed at her home in Kempston. Davenport was stabbed in the legs, lost 50% of the blood from his body] and underwent emergency surgery for injuries described as serious. Two men were arrested the same day. At Bedford Magistrates Court, on 24th August 2009, 25 year-old Worrell Whitehurst, the boyfriend of Davenport's sister, was remanded in custody charged with grievous bodily harm with intent in connection with the attack on Davenport, and with assault occasioning actual bodily harm to his mother. Due to the nature of the injury, Davenport's career is believed to be under threat

On 28th October 2009, Davenport was charged with assault on his sister, Cara Davenport, in the same incident in which he was stabbed. In January 2010, West Ham suspended Davenport's wages until completion of the court case alleging breach of contract on his part when he was involved in the assault in August 2009. On 25th January, Davenport pleaded not guilty to the charge at Luton Crown Court and the case was adjourned until 2nd August 2010 at the same court. On 17th March 2010, his contract with the Hammers was terminated by mutual consent.

In July 2010 Davenport was cleared of trying to attack his pregnant sister during the incident while a man was jailed for six years for a knife attack on the footballer.

On 5th August 2010, it was reported that Davenport was training with Notts Forest. "We're giving Calum the opportunity to train with us while giving ourselves the chance to look at him," said Forest boss Billy Davies. He then joined Leeds on trial.

On 3rd September 2010, Davenport signed for Wootton Blue Cross of the United Counties League in a bid to regain fitness before returning to the professional ranks.
On 18th March 2015, Davenport was arrested by Bedfordshire Police on suspicion of assault after playing in a local league match while playing for Elstow Abbey Football Club against Cranfield United  On 22nd March, Davenport was expelled from the club following the incident which had occurred in the changing room