The 14-year-old sung 'And I'm Telling You' from the musical Dreamgirls to claim the title and an $250,000 (£165,250) prize.
Vidgen, who hails from the Sydney area, beat Melbourne magician and escapologist Cosentino in Tuesday evening's grand final.
The Herald Sun reports that Vidgen signed a record deal with Sony Music moments after leaving the stage and quotes the teenager as saying that he would release a single that evening "if they let me".
Sony is thought to be releasing his first single 'Yes I Am' tomorrow.
Vidgen had impressed the judges at his very first audition with a performance of Whitney Houston's 'I Have Nothing', leading Kyle Sandilands to tip him as a potential winner and Brian McFadden to say that he was "incredible... you are a superstar".
The singer has reportedly been receiving death threats. However, New South Wales Police said that they have not yet received a formal complaint from Vidgen or his family, which would allow them to investigate further.
Watch Jack Vidgen's first Australia's Got Talent audition below: