The Belarusian came from a set behind to beat China's Li Na 4-6 6-4 6-3 in two hours, 41 minutes.
Speaking to the Rod Laver Arena afterwards, Azarenka said: "It's been a real long two weeks for me.
"I really love coming here. I will always have a very special memory of this court, it will be in my heart forever."
Azarenka signed off her victory speech by wishing the crowd a "Happy Australia Day". The match was delayed for 10 minutes after the third game of the final set for Melbourne's celebratory fireworks.
Victory for Azarenka ensured that she retained her status as world number one. She also becomes the eighth woman to successfully defend the Australian crown.