The two era-defining players have defied odds, rankings and injuries to make the final two in Melbourne, and it is sure to be a superb occasion as the pair go head-to-head for the ninth time in a major final.
Both had to come through gruelling five-set matches to make the final, and Federer could have an advantage from getting an extra day's rest.
Here is how to catch the action.
Date: Sunday, Jan. 29
Time: 8:30 a.m. GMT; 3:30 a.m. ET; 7:30 p.m. local
TV Info: Live on British Eurosport 1 (UK) and ESPN (U.S.)
Predicted Winner: Roger Federer
Federer, 35, last won a Grand Slam in 2012 at Wimbledon, while 30-year-old Nadal's last major triumph was at the 2014 French Open.
Having utterly dominated their sport in the late 2000s, the pair's respective stars have waned recently as Novak Djokovic and Andy Murray have risen to the top.
Ahead of the first Grand Slam of 2017, it was Murray and Djokovic who were deserved favourites to win, but early exits from both paved the way for Sunday's distinctly retro but much-anticipated final.
Due to his recent long-term injury, Federer came into the tournament ranked No. 17 in the world, while Nadal was No. 9.
Both have come through two five-setters on their route to the final—Federer against Stan Wawrinka in the semis and Kei Nishikori in the fourth round, Nadal against Grigor Dimitrov in an epic last-four clash and Alexander Zverev in the third round.
The atmosphere is sure to be incredible on Rod Laver Arena, but it is unlikely either Nadal or Federer will concern themselves with exterior pressure given the number of times they have appeared together in such crucial matches.
Nadal's overriding emotion upon earning his spot against Federer in this year's Melbourne final was one of excitement:
There have arguably never been two better players to have picked up a tennis racket, but there were many who thought they may never meet again in a final, per BigSport:
Federer will be looking to extend his record haul of Grand Slam titles by claiming an 18th on Sunday, while Nadal can move ahead of Pete Sampras and take over second place outright in the history books if he claims a 15th major title.
There is a huge amount at stake for two legends of the game, and if their previous bouts are anything to go by, it should be an epic occasion to decide the 2017 Australian Open.