The couple who have been together for 10 years and have two children together are planning to tie the knot in a chapel on the grounds of their $1.25 million French estate in late April.
A source said: "They're a very private couple. It's no surprise they'd want to celebrate at their home."
Rumours sparked last month when Johnny was seen shopping for an engagement ring in California.
Johnny previously admitted he was reluctant to get married because he adores Vanessas surname.
The Pirates Of The Caribbean Star said: It would be a shame to ruin her last name! It's so perfect - Vanessa Paradis. So beautiful. It would be such a drag to stick her with Paradis-Depp. It's like a flat note!
But if she ever said, 'Hey, let's get hitched', I would do it in a second
It's reported the pair are keen to keep the ceremony as intimate as possible, and will only invite 50 of their closest friends and family.
However is most likely to be a star studded affair as director Tim Burton is expected to act as best man, while Rolling Stones rocker Keith Richards is also due to attend.
An insider said: "Keith and Johnny are good pals. Johnny's portrayal of Jack Sparrow in 'The Pirates of the Caribbean' was partly inspired by the old rocker, and Keith had a cameo in the second sequel."
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