The massive statue is missing the tip of a thumb, the Rev. Osmar Raposo, the site's manager told Sky News.
The damage was done during a thunderstorm Thursday, when Brazilian officials said satellite technology counted more than 40,000 lightning strikes in the region over a 3-hour span.
Striking photos show the concrete statue glowing white against a black night sky as the lighting bolt hits it.
The statue will undergo repairs next month, Raposo said.
A 2007 survey named the statue -- which stands 125 feet tall atop Mount Corcovado -- one of the seven new wonders of the world.