Federer scented blood and quickly polished off the first set before breaking Cilic to lead 3-0 in the second.
Roger Federer now has nineteen Grand Slam singles titles.
Federer was rusty upon his return to the grass in Stuttgart but hit his stride in Halle, where he claimed his ninth title at the Wimbledon warm-up tournament without dropping a set. Cilic has also delivered 130 aces, the second most for the tournament, behind only Sam Querrey with 139.
The Swiss star returned back to his menacing best following the radical transformation he made to his playing schedule since slumping to a defeat to Canadian Milos Raonic in the semi-finals of the Wimbledon in 2016.
From tennis players to footballers to cricketers, all have hailed Federer's feat.
And becoming the first man to lift eight singles titles at SW19 was also something Federer had never expected, but was a pleasant addition to an already sensational career.
'I hope it isn't my final match here and hopefully I can come back next year and defend the title'.
Merciless and majestic in equal parts, Federer's stirring victory ended a five-year Wimbledon title wait and came 14 years after he first reigned on London's hallowed lawns in 2003.
Federer is 6-1 against Cilic, but the big-serving Croat beat Federer in the U.S. Open semifinals in 2014 on his way to his only major title. He had for the first time won the French Open and with Nadal out of the tournament, it was Federer's' to loose and he did not disappoint.
"Better than holding the trophy and winning today is to be healthy", said Federer. I kept on believing and dreaming and here I am today with the eighth.
"I've got to take more time off, I don't know". During the match, his foot was giving him extreme troubles, and at one point Marin Cilic started to cry because of the pain he was enduring.
"Obviously it was very tough emotionally because I know how much I went through last few months in preparation with everything".