They have been engaged for over three years.
The 36-year-old actor hinted that the pair may already be married during the Cinema Society Screening of his new film, Locke, in New York on Thursday.
Speaking about how supportive Charlotte is about his work, Tom said: “Well, my wife is an actor as well so she sort of gets it,” reports the Daily Mail.
“Apart from that, I’m a pain in the ass, really,” he added. “You know what I mean? Like any other boyfriend.
“Isn’t that part of being in a relationship?”
While the pair are private about their relationship, Tom couldn’t help but praise beautiful brunette Charlotte when asked what he loved most about her.
“Aw, she’s pure. She’s just a very kind, pure person,” he said.
Tom and Charlotte met on the ITV set of Wuthering Heights in 2009 and got engaged in 2010.
Despite his words, the Inception star has not been seen with a wedding ring on his finger.
The British star has been busy promoting his latest film Locke but will soon return to TV screens in the second series of BBC period crime drama Peaky Blinders.
He is also set to play Elton John in new movie, Rocketman – despite the fact he admits he can’t sing.
Click here for more on how Tom is going to handle that role.