Nadal's 10th Roland Garros title is his 53rd on clay, the most won by a player on the surface in the Open Era.
Nadal led their head-to-head record at 15-3 against Wawrinka, also owning an advantage of 6-1 on clay.
Nadal moved into sole possession of second place in men's majors, pulling away from American Pete Sampras and once again getting to within three of Federer, who skipped Roland Garros to prepare for the grass-court swing.
Two days after turning 19, Nadal became the youngest man to win a major title since Michael Chang was 17 at the 1989 French Open. The 29-year-old is just New Zealand's second Grand Slam victor in the modern era.
After the heartbreak of losing the Australian Open final to Roger Federer earlier in the year, emotion overcame Nadal after the match, but he was ruthless for its entirety. It was his 18th crown.
Nadal dominated the contest from start to finish against Wawrinka, who was simply helpless to get into the match, with all the key points going the way of the Spaniard.
Cradling the trophy like one would a new-born, Nadal graciously accepted the thunderous applause Philippe Chatrier afforded him, clearly struggling with the emotions that were understandably running through head. But the barrel-chested "Stanimal" was powerless as Nadal turned the final into an exhibition of his clayclourt supremacy- taking his French Open record to an eye-watering 79-2.
"The nerves, the adrenaline I feel when I play on this court, it is impossible to compare.it is the most important event in my career, to win again here is impossible to describe", he said.
"I don't care about the games I lost or not, or sets, these kind of things - the only thing I care is I have been playing very well during the whole event, and I was able to win all the matches", Nadal said. To put that in perspective, Wawrinka, comfortably the second-best player this year at the French Open, lost 102 games over the course of seven matches.
"Two weeks or three weeks ago, I was really down, not winning matches in Masters 1000, not playing my best tennis, a lot in doubt in my game when I was playing", Wawrinka said.
But Nadal's 10th title at Roland Garros is just the tip of the iceberg when it comes to the incredible nature of his success. "But the feeling I have here is impossible to describe and hard to compare to another place".
Third seed Wawrinka arrived full of confidence as, at 32, he tried to become the oldest French Open victor since Andres Gimeno in 1972. From there it was all over for Wawrinka, who dropped serve to begin the third and was also broken two more times after that.
With the win, Nadal extended his head-to-head lead over Wawrinka to a stellar 16-3, and improves to a flawless 10-0 in French finals. He won all 12 service games, made a mere 12 unforced errors, and won 94 total points to Wawrinka's 57.
It was the beginning of the end for Wawrinka, who would have felt he needed to take the first set to be a chance.
"It's always been an honor to play against you", Wawrinka told Nadal as he addressed the crowd.