Mantle, 55, played Greatjon Umber during Season 1 of "Game of Thrones." He also is famous for playing surgeon Mike Barrett on the BBC medical drama "Casualty."
The Guardian newspaper said the 6-foot-5-inch-tall actor was injured early Sunday morning after asking a group of men to quiet down outside his Newcastle hotel room.
A 32-year-old man has been charged with wounding with intent and is scheduled to appear before magistrates next month.
"He is very shaken and shocked by what has happened. You don't expect this kind of thing to happen in a hotel," a spokesman for Mantle's agents, the London-based Sarahband Associates, told the newspaper. "The part of the ear that was bitten off was found and sewn back on. Mr Mantle said the police, ambulance and hospital staff were amazing."
The actor was Newcastle performing in the play "The Ladykillers" at the Theatre Royal, but has left the production due to his injury.