The Spanish superstar is searching for his 12th title at Roland-Garros as the competition witnesses a repeat of the 2018 final.
Thiem eliminated Novak Djokovic in a thrilling five-set semi-final but will be the heavy underdog against Nadal in Paris.
Date: Sunday, June 9
Time: 10 a.m. (ET)/3 p.m. (BST)
TV Info: NBC (U.S.), Eurosport, ITV 4 (UK)
Men's Final Preview
Thiem continues to build a reputation for himself on clay but must now tackle one of the greatest ever on the surface.
The 25-year-old could not face a tougher sporting task than having to beat Nadal to win the French Open.
Roland-Garros is the Spaniard's playground. He has won the tournament 11 times, including the last two titles after overcoming injuries and a loss of form that saw him fail to win the event in both 2014 and 2015.
Nadal was ruthless in beating Roger Federer in the last four, winning in straight sets against his great rival.
It was a complete display that will have been noted by his forthcoming opponent:
Thiem will be reminded of his experiences in the final 12 months ago, in which Nadal was irrepressible as he claimed the title in straight sets, 6-4, 6-3, 6-2.
There's only two places between the pair in the tournament seedings, but Nadal's experience at this level gives him a mammoth advantage.
Speaking before his victory over Djokovic, the No. 4 seed Thiem said he feels his form has improved each round, and he understands the huge task ahead of him as he searches for his first major win:
It's difficult to see past Nadal collecting yet another trophy in Paris, but there could be a passing of the torch if Thiem shocks the world.
The Austrian has continued to prove he is one of the best, and the next hurdle to jump is to beat a legend to capture a noteworthy championship.
However, the 33-year-old Nadal continues to amaze with his athleticism and ball-striking and will be looking to extend his record number of French Open titles to 12; Bjorn Borg's previous record stood at six in the Open Era.