The Swiss master stormed to his latest victory - a fourth in as many finals this year - in just 53 minutes and appears in prime form with little more than a week to go until he begins his pursuit of an eighth Wimbledon crown.
"It has been a hard year, I have spent a lot of time on practice, training and rehab so it is nice to be back on court", said Federer, who suffered a surprise defeat by Tommy Haas in Stuttgart earlier this month.
The big-serving 35-year-old, ranked 32nd in the world, had lost on a tiebreak in his only previous final appearance in 2014, blowing a match point on the way, and he said: "I can not believe I have finally won this tournament".
"It is a dream to start a final like that and to pull through then". You could make a case for either side, but I'm giving the edge to Federer, as he's just too consistent and still pounces on any mistakes his opponent makes.
Fourth seed Cilic battled past Gilles Muller of Luxembourg 6-3 5-7 6-4 following an hour's delay to the original order of play, while Lopez came through 7-5 3-6 6-2 after an interrupted encounter with Grigor Dimitrov later on Centre Court.
Federer has won four titles this year, a tally matched only by long-time rival Rafael Nadal.
This is set to be a really interesting match as it is between two players are at two very different stages of their career. Find us on Facebook too! "It was actually not bad to play a bit".
Cilic saved the first match point against him with an ace, and a second with a forehand volley, before a wide forehand saw Lopez take his chance at the third attempt.
The unseeded Spaniard is expecting another stern test against Cilic.
Prior to Sunday's final, Zverev hailed "Roger (Federer) the best player of all time on grass" and it seemed like the youngster was overawed by the moment, standing face-to-face with his childhood idol.