The 32-year-old Londoneer held off the challenge of Olympic 5,000 and 10,000 metres champion Mo Farah and the US Open and Olympic men's singles tennis champion Andy Murray, who finished second and third respectively.
Ennis claimed the Sportswoman of the Year prize for the third time in four years as she who polled two-thirds of the votes cast.
The 26-year-old from Sheffield held off double Olympic sculls gold medallist Katherine Grainger, who was runner-up, while double Olympic cycling champion Laura Trott finished third.
Ennis was also named as the winner of the Pat Besford Trophy for the outstanding performance of the year.
Europe's Ryder Cup team, including seven British golfers led by Ian Poulter, Rory McIlroy and Luke Donald, were runaway winners of Team of the Year, having retained the trophy in the United States with the greatest last-day comeback ever seen at the event.
Runners-up were gold medal Olympic rowers Anna Watkins and Katherine Grainger, with Champions League winners Chelsea third in the voting.
Meanwhile, due to the huge success of the London 2012 Paralympics, there were two awards for the Disabled Sports Personality of the Year with wheelchair racer David Weir taking the men's prize and cyclist Sarah Storey the women's.
Weir won four gold medals at London 2012 in the 800, 1500 and 5,000 T54 metres as well as the while Storey won four cycling golds in the individual C5 pursuit race, the time trial C4-5 500m, the individual road time trial C5 and the individual road race C4-5.
There was also a prize for leg amputee sprinter Jonnie Peacock who collected the Spirit of Sport prize after winning gold in the men's 100m T44 final at the London 2012 Paralympics.
Elsewhere England and Arsenal footballer Alex Oxlade-Chamberlain claimed the Best International Newcomer prize.
Sir Michael Parkinson gave his SJA President's Award to the Olympic double sculls gold medallists Grainger and Anna Watkins while the SJA Chairman's Award went to tennis player Jonny Marray, who won the Wimbledon title with his Danish partner after only getting into the tournament on a wildcard.
Finally, the JL Manning Award for an Outstanding Contribution to Sport went to London 2012 chairman Sebastian Coe for his role in staging the Olympic and Paralympic Games.
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