The 35-year-old Swiss continued his resurgent season and unchallenged run, dominating Marin Cilic of Croatia 6-3, 6-1, 6-4 on Centre Court at the All England Club in London.
Federer becomes the oldest man to win Wimbledon in the Open era, which dates to 1968.
Federer won every set he played in this year's tournament. He last won the grass-court major in 2012.
Federer won the Australian Open in January for his 18th Grand Slam title and then decided to skip the clay-court season, including the French Open, to prepare for the grass and hard-court seasons, with his eye on Wimbledon.
Federer, three weeks shy of turning 36, is now 7-1 in head-to-head matches against Cilic, who beat Federer in the U.S. Open semifinals in 2014 on his way to his only major title.