Finally!!! An anime question!!!!
Well till date there have been 7 hokages(not including Danzo). As such I'm going to name them in increasing order of speed.
7. Tsunade Senju(Fifth Hokage): If you've watched the show then you know that Tsunade's never really relied on her speed as on of her strengths so it's no surprise that she finishes last.
6. Hashirama Senju(1st Hokage): Just like his grand daughter Tsunade, speed wasn't his strongest point and considering how powerful he was and the large expanse that his wood style ninjustsu took up, frankly, he didn't need to be fast.
5. Sarutobi Hiruzen(3rd Hokage): Coming in at number 5 is the monkey king summoner himself. He wasn't shown to exhibit feats of extreme speed through out the show but he was still able to fend off the first and the second Hokage all by himself even when he was well into his 50s
4. Hatake Kakashi(6th Hokage): His mastery of the raikiri alone is an attestation to how fast he is. He's been shown to be extremely fast even from when he was just a kid.
3. Tobirama Senju(2nd Hokage): The original creator of the teleportation technique that the 4th Hokage was made famous for, Tobirama was no doubt one of the fastest ninjas alive, and he was only bested by the next two names on the list.
2. Namikaze Minato(4th Hokage): He was touted as the fastest ninja that ever lived, even gaining the title of Yellow Flash. In the 3rd great ninja war, his speed was feared so much that all enemy ninjas were given orders to flee on site once they saw a ninja matching his description.
1. Uzumaki Naruto(seventh Hokage): Not just the fastest Hokage, but the fastest character in all of Naruto. His speed has seen him surpass the likes of the fourth raikage, his father and quite possibly even Shisui Uchiha who was believed to be the fastest ninja alive during his time. He's undoubtedly the fastest of all the Hokage.