Indeed there are. Actually its weird when you think about it because some actors and characters are too similar for it to be true.
At least during some point in our lives, we've imagined ourselves as superheroes saving the lives of others with our powers and being adored for how awesome we look whilst doing so. Just me? Well this typical protagonist character that we look up to is fiction created from our imagination; but what about the imagination of others. Talented artists and writers like Jack Kirby and Stan Lee have created numerous characters of various looks and personalities; and that's just the comic book genre. Therefore, statistically speaking there are a likely number of people in the world who look exactly like the living embodiment of a fictional character.
3 words. Robert Downey Jr. Nobody can deny that this man is the only person who can play the billionaire, playboy, philanthropist that is Tony Stark. He looks, talks and acts exactly the way that the traditional comic book character did.
Even the creator Stan Lee says that:
"This man is born to be Iron Man. He looks exactly like what I had in mind when I created Tony Stark."
Stan Lee Interview - Need I say more
Originally actor Dougray Scott was cast as Wolverine in the first X-Men movie since he looked like the actual character in terms of how Wolverine in the comics is around 5' 3". Though, due to a somewhat unfortunate accident before production, Scott got injured. He was unable to play the role and this led to the casting director to look back at the other actors who auditioned (Jackman's audition). Luckily the one and only Hugh Jackman obtained the role for obvious reasons. Firstly, he is physically built like the character, which combined with the patented wind-swept hairstyle and sideburns make Jackman's acting all that more believable.
Unfortunately, we come across the problem that at some point these ideal actors will not be able to portray the characters forever. In fact, both of the actors have announced that in the foreseeable future they will relinquish their roles and move onto other things.
Clearly there are many other actors which I haven't mentioned, but I'd love to hear who your favourite actor look-alikes are. As well as who you would recast as the new Iron Man and Wolverine.