Nadal joins Australia's Margaret Court as the only player to win 11 titles at the same major.
Nadal remained implacable in the homestretch, intent on ignoring his temporarily impaired hand, outracing the rainclouds that hovered close and low but didn't erupt, and trying to outrun, outhit and outwit a player who was 11 years old when he won his first title here in 2005.
Veteran pair Nadal and Federer have won the past six Grand Slams as their younger rivals struggle to dislodge them at the pinnacle of the game. In a matter of 57 minutes, he bagged the first set 6-4 and then extended his dominance to win the second set 6-3.
Dominic Thiem was vying for his first Grand Slam title on Sunday.
Last year, he lost 15-13 in the fifth set of his last-16 tie against Gilles Muller. One of the hardest hitters of the tennis ball, Thiem, playing his maiden Slam final, more than held his ground.
Even when Nadal showed a sign of weakness, undergoing repeated treatments to an arm cramp in the third set, Thiem was unable to capitalise as like a wounded lion, Nadal immediately upped the tempo in order to bring proceedings to an end as quickly as possible. Whatever the issue was, Thiem could not earn the break back-giving up another one while serving down 4-2-and Nadal took the third set and the title.More news: Xbox commits to cloud gaming, but consoles aren't going anywhere
Nadal's win-loss record at the French Open, his only two losses coming against Swede Robin Soderling in the fourth round in 2009 and against Djokovic in the quarterfinals in 2015.
Thiem undid all his good work in the next game, netting an easy volley on the first point and gifting Nadal three more unforced errors to hand over the first set. This season no other player, not even the undisputed King of Clay, can count as many match wins on the red dirt as Thiem.
Federer's 11 are at Wimbledon, and if Nadal beats Thiem on Sunday, he'll keep his flawless French final mark; he's never lost in the ultimate match at this event. "Bravo. To me it's been still great two weeks".
Thiem has beaten Nadal twice recently, so an upset was not out of the question.
In an unusual breach of protocol, Nadal walked to his chair after missing a first serve at 2-1, 30-love.
"I have to come back to speak with my team", said Nadal, who pulled out of Queen's in 2016 -because of a serious wrist injury and previous year because of exhaustion.
Thiem found some life and threatened with a break point in the seventh game, but Nadal broke his pace with a drop shot and finished it off with a passing shot, holding for 5-2.