There's nothing the movie industry loves more than a true story. You can pour over comic books or jet off into space all you want, but few things can match just how crazy the real world can get.
This naturally creates a problem that can be less of an issue in totally made up movies; authenticity. There's an added pressure to make period dressing accurate and, rather than picking an actor based on a character description and maybe a concept sketch, the film's team have to cast someone can at least skew moderately close to a fully existing person.
Sometimes you may see a real person actually play themselves. United 93 had various people, most prolifically FAA National Operations Manager Ben Sliney, cast as themselves in a recreation of the September 11 terrorist attacks. That's not really feasible much of the time, with various tricks used to get a faithful representation.
What's most common nowadays are feel-alike castings. Getting a total look-alike can be tricky and if not boasting a good performance with it can appear gimmicky. Getting a great actor, making them look a little like the person but letting their performance be the real selling point is the way to go. Of course, this can lead to some people with an on screen counterpart that looks nothing like them. Today we bring you fifteen of those people.