Chaplin was an English comedic actor and filmmaker. Chaplin became one of the most famous actors as well as a notable filmmaker, composer and musician in the early to mid "Classical Hollywood" era of American cinema. 
In My Autobiography by Charlie Chaplin, he writes about a dinner at which Sergei Rachmaninoff also attended:
"Someone brought the topic round to religion and I confessed I was not a believer. Rachmaninoff quickly interposed: "But how can you have art without religion?"
I was stumped for a moment. "I don't think we are talking about the same thing," I said. "My concept of religion is a belief in a dogma--that art is a feeling more than a belief."
"So is religion," he answered. After that I shut up. 
In his son's book, My Father, Charlie Chaplin, (pp. 239-240) he recalls his father stating:
"I'm not an atheist," I can remember him saying on more than one occasion. "I'm definitely an agnostic. Some scientists say that if the world were to stop revolving we'd all disintegrate. But the world keeps on going. Something must be holding us all in place--some Supreme Force. But what it is I couldn't tell you." 
NOTE: Chaplin is quoted as saying, "By simple common sense I don't believe in God, in none" in the book Manual of a Perfect Atheist by Eduardo Del Rio Garcia. This would appear to be a straightforward profession of atheism. However, the only place this quote turns up is in that book and it is uncited. Unless new evidence surrounding this quote is unearthed, it should not be regarded as a valid quote from Chaplin.