The 22-year-old Italian had lost just one set in the tournament before facing Daniil Medvedev in the final
Sinner, who started the tournament as the number four seed, reached his first major final in Melbourne.
It was the first Grand Slam win for the 22-year-old Italian racket, who lost just one set before reaching the final.
The Italian produced an impressive performance to reach Sunday's Australian Open final, ending 10-time Australian Open champion Novak Djokovic's 33-match winning streak at Melbourne Park with a four-set semi-final victory. Sinner had lost his only set before the final to Djokovic in the semifinals.
Djokovic had never lost in Australia after reaching the semifinals.
Medvedev won the 2021 US Open title but lost the other four major finals he played in, including in Australia in 2021 and 2022.
After coming from two sets down to beat Alexander Zverev in the semifinals, Medvedev became the first player since Pete Sampras in 1995 to come from two sets down to reach the final in Australia.