We finally have confirmation that Albus Dumbledore will be appearing in Fantastic Beasts and Where To Find Them 2, and we're hopeful that means he'll have an even bigger presence as this budding series moves forward. But who will play him? That has yet to be determined, so what better time to speculate over who might snag the role of Dumbledore in the anticipated followup for the upcoming Harry Potter spinoff.
It's worth noting a couple of things before we get to the list. The first is that we're going to assume that whoever plays Dumbledore will be from somewhere in the United Kingdom. That's yet to be confirmed, but we're going to ride with that assumption. Dumbledore is British, so hopefully he'll be played by a British actor.
The next is that Dumbledore would've been in his mid-forties in the 1920s, so (factoring in Hollywood's typically flexible view on actor/character ages) we're assuming they'll cast someone within the range of late thirties to early fifties.
Finally, we don't really know what Dumbledore's personality was like in his younger years. Maybe he was really just a 40-something version of the Dumbledore we came to know and love in the Harry Potter books and movies, but I'm inclined to think life-experienced shaped him into the eventual Hogwarts headmaster. So we can't really pinpoint an actor by personality type.
All of the above in mind, here's a list of (mostly) British actors who could fit the part of Albus Dumbledore.
I'm dropping this name first, because he's among my favorite choices for the part. At 45, Damian Lewis is the perfect age to play 1920's Dumbledore. Though he's spent a lot of his career on the small screen (Homeland, Life, Billions), he's no stranger to feature work, and certainly has the talent to take on a role like this. It's not hard to picture Damien Lewis playing the kind and compassionate side of Albus Dumbledore, and then easily shifting gears to be the formidable magical force if and when the time calls for it.