Both made history, with Djokovic becoming the first man to win seven titles at the Australian Open and Osaka adding to her success by becoming the first Asian to be ranked world number one in singles.
Here, Press Association Sport picks out five things we learned from the tournament.
Djokovic can win the lot
With the asterisk that he was not playing Rafael Nadal at his fittest or best, Djokovic's final performance was simply tennis on another level. His remarkable physical abilities, combined with his efficient strokes and ability to guide the ball into the corners add up to the perfect package on a hard court. His apparently insatiable desire for titles means it seems less a question of 'Can he win the calendar Grand Slam?' but rather 'Who can stop him?'
Osaka can win a lot
With the emergence of a genuine, reliable superstar in unassuming 21-year-old Osaka, women's tennis finds itself in a very healthy place indeed. After blowing away opponents at the US Open, Osaka showed here that she can find a way to come through tricky matches and regroup when times get tough. It would be a surprise if she proved as effective on clay, but expect her to be a challenger at Wimbledon.
Murray might not be finished yet
From despair to redemption to hope, Andy Murray's stay in Melbourne may have been a short one but he certainly left his mark. It would be a surprise if the Scot does not decide to have hip resurfacing surgery and potentially give his career another go. There are no guarantees, but doubles specialist Bob Bryan spoke extremely positively about his experience after the same operation.
The guard remain unmoved
John McEnroe may have hailed Stefanos Tsitsipas' victory over Roger Federer as the changing of the guard in men's tennis, but that was quickly made to look distinctly premature as Djokovic and Nadal steamrollered all-comers. Tsitsipas was the breakthrough star of the tournament and looks ready to challenge for titles soon, while Frances Tiafoe also made a big leap forward, but the gap remains a sizeable one.
There can be too much tennis
Late finishes are nothing new but the sport must look at its scheduling and decide whether the current arrangement is really sensible. Johanna Konta and Garbine Muguruza did not begin their second-round match until 12.30am and finished after 3am in front of a handful of spectators. There is no need to play tennis in the middle of the night. As Muguruza said: "I seriously can't believe that there are people watching us at 3.15. I mean, who cares?"