But he faced strong competition for the BBC Wales award in a year of unprecedented Welsh sporting achievement.
Wales had three Olympic gold medallists in cyclists Cooke and Geraint Thomas, plus rower Tom James.
Swimmer David Roberts also triumphed in Beijing, taking four golds to bring his all-time Paralympics haul to 11 golds.
Calzaghe - who had won the award three times previously - cemented his place as one of boxing's all-time greats by stepping up from the super-middleweight division he ruled for more than a decade to beat American greats Bernard Hopkins and Roy Jones Jr at light-heavyweight.
Other awards at the event in Cardiff's Swalec Stadium included team of the year, won by Cardiff City FC.
In May, the club reached the final of the FA Cup for the first time in 81 years and only the third time in their history.
The Championship side had beaten Premiership side Middlesbrough in the sixth round and went on to a semi-final win over Barnsley at Wembley before losing 1-0 to Portsmouth in the final.
But Cardiff had faced a significant challenge for this award from Wales' Grand Slam-winning rugby team.
And amateur sport was rewarded with the Welsh Sports Unsung Hero accolade, won by rugby and boxing volunteer Cliff Williams from Pontyclun in Rhondda Cynon Taf.
He was recognised for giving up his time for more than 30 years to help young people improve their lives through sport.
Mr Williams is now in contention for the UK Unsung Hero award made at Liverpool's Echo Arena on Sunday 14 December.
The lifetime achievement award went to retired snooker legend Ray Reardon in recognition of his dominance of the sport for over a decade.
A deadly long potter and tactician in his prime, he was undefeated in 17 world championship matches and won the title four years in succession.
The Carwyn James junior sportsman of the year title went to Caerphilly-born teenage football sensation Aaron Ramsey.
Now playing for Arsenal and Wales, Ramsey transferred to the Gunners from Cardiff City in 2008, having been the Bluebirds' youngest ever senior player at the age of 16, breaking the previous record set by current Wales boss John Toshack.
Carwyn James young sportswoman of the year was golfer Amy Boulden.
Boulden, 15, of Llandudno, has risen through the ranks of the Welsh Girls squad and was included in the full Welsh ladies squad for the first time in 2008, also earning selection for the Great Britain and Ireland squad.
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