The Pirates of the Caribbean: On Stranger Tides says he has no intention to propose because he thinks their relationship is perfect as it is.
They have two children, Lily Rose, 11, and nine-year-old Jack.
He told America's OK! magazine: "We've never married and that's how it is going to stay - for now. As one of our presidents once said, 'If it ain't broke, don't fix it.' We just haven't done the big public vow thing. It doesn't seem necessary for us. Others may want to go down that road - we don't."
PHOTOS: Vanessa Paradis in concert
Despite his successful acting career, Depp says his greatest achievement is meeting Paradis and raising a family with her.
The 47-year-old heartthrob said: "If you call meeting Vanessa an 'achievement', it was certainly that. It came at the right time. We were both ready for children, and she's given me Lily Rose, who is now 11 years old, and Jack, who's 9. I saw Vanessa across a room - and I first saw only her back! But I immediately thought: "That's the woman for me." That was nearly 12 years ago."