The typically clean-shaven Homeland star is letting his facial hair grow out as part of his preparation for Queen of the Desert, but he reveals he's using his new look to spread awareness and raise cash for the Movember movement, during which men worldwide are encouraged not to shave their upper lip for a month to draw attention to the cause.
He explains, "I'm actually going to do a film with Werner Herzog just after Christmas, and (with) Nicole Kidman, and he (his character) is an Edwardian German. Takes place in the First World War and he has an amazing, kind of handlebar moustache... so I started early to try just to try and get there."
However, Lewis admits not everyone is a fan of his moustache: "My wife does not like it. She's being polite and saying she does."
The actor isn't the only celebrity supporting Movember this year (13) - Ashton Kutcher is also taking part in the hairy campaign.