The singer beat Donal MacIntyre in the final jump of the series to be declared the winner of the Channel 4 winter sports show.
Both competitors - who joined the competition late as stand-ins for Henry Conway and Melinda Messenger - took on the medium-sized K24 jump.
However, McElderry opted to jump the K40 in the final round, while MacIntyre remained on the K24. McElderry recorded the greatest distance at 17.5 metres.
Earlier today, Sir Steve Redgrave and Marcus Brigstocke were forced to pull out of the competition due to injuries sustained in the ski cross event.
Redgrave decided to opt out of the final after an old injury caused him pain in today's training session.
Brigstocke "wiped out and injured his knee" after taking on the course's final jump, meaning he was unable to jump on tonight's show.
After being declared the winner, McElderry told Davina McCall: "I've had an absolute blast with Donal. We've had so much fun this week and he, out of everybody, has the best sportsmanship I know."
MacIntyre added: "Joe, from day one, was always the crown elect. We're so proud of him. Well done, buddy."