Representing Japan, the 6-4, 6-3 win was Osaka’s second Melbourne crown following a first title in 2019.
In terms of other Grand Slams, she's also a two-time U.S. Open champion on the surface after winning at Flushing Meadows in 2020.
Osaka is one of the home country’s biggest Olympic gold medal hopes at the Tokyo 2020 Games in 2021.
The tennis tournament will be played on a hard surface in Japan.
Here are six reasons to be excited about her planned involvement in the Olympic Games, with the first matches scheduled for 24th July 2021.
Osaka: Big player for the big games
Osaka has now played her way into four grand slam finals. She's won all four.
She's never lost in the second week of one of the major tournaments in the tennis calendar.
The 23-year-old is also the first Asian player to hold the world number one spot in the rankings.
Osaka a big Japanese home hope for Tokyo Olympic gold
Aged three, she moved to the United States, where she lived and trained as a youngster.
She chose to represent Japan after holding dual nationality.
Osaka making an impact on and off the court
In August 2020, Osaka joined NBA players in refusing to play, after the police shooting of Jacob Blake in Kenosha, Wisconsin.
She decided to withdraw from her semi-final at the Cincinnati Open - held in New York - with the WTA and ATP then backing her stance by suspending play for the day.
"As a black woman I feel as though there are much more important matters at hand that need immediate attention, rather than watching me play tennis," she said on social media.
The way she has continued to speak out about social justice ever since has been widely praised.
Jennifer Brady, who Osaka beat in the 2021 Australian Open final said of Naomi, "She's such an inspiration to us all... I hope young girls at home are watching and inspired by what she's doing."
Osaka inspired by Kobe Bryant
Serena Williams has dominated women’s tennis throughout her impressive career.
Osaka channelled a special mentor in order to beat Williams in straight sets in the 2021 Australian Open semi-finals.
She revealed that she still thinks of the late basketball legend Kobe Bryant every day.
"Believing in yourself is something that's not always easy to do for anyone, but that was one thing I took from Kobe," Osaka said in an exclusive interview with Insider.
"Self-doubt helps nobody, and if you cannot believe in yourself, you cannot expect others to believe in you."
She regularly pays tribute to the two-time Olympic gold medal-winning NBA star, wearing his L.A. Lakers gear after every match of her 2020 U.S. Open win, and after the 2021 Melbourne semi too.
Osaka is into gaming
The average training day for Osaka lasts around four hours on court.
She's been known to spend a similar amount of time away from tennis, playing video games like Overwatch.
On court, she's known for her aggressive point winning style.
She has a different approach to Overwatch.
"I’m not that great at attacking,” Osaka said to GQ.
“My aim is not that amazing, so I’d just rather be a shield or something.”
Osaka at one with the natural world
Osaka's shy and retiring interview style has endeared people to her throughout her success.
She's also seemingly popular in the natural world too.
A butterfly seemed enamoured with Naomi during a match at the 2021 Australian Open, repeatedly landing on her body and face as she was trying to serve.