The actor's three-year deal with Dior is worth north of $20 million ... according to Variety. It's the most lucrative men's fragrance deal of all time.

TMZ broke the story ... Johnny signed back on with Dior in August, following his big-time legal win over Amber Heard. At the time, we were told Johnny and Dior agreed to a multiyear deal worth at least 7 figures ... and now there's more clarity on the contract details.

With his $20 million deal, Johnny overtakes Robert Pattinson as the highest-paid spokesman for a cologne. Robert set the mark in 2012, when he signed a 3-year, $12 million deal to promote Dior Homme.

Johnny's nearly tripling the amount Chanel paid Brad Pitt to be the first ever men's face behind Chanel N°5 perfume, Brad reportedly signed for $7 million in 2012 for a series of ads.

As we first reported ... Johnny's new deal with Dior was cemented last summer after famous fashion photog Greg Williams and honchos from the French fashion and cosmetics giant attended one of Johnny and Jeff Beck's rock concerts in Paris.

We were told Johnny did a photo shoot with Greg before and after the Paris show, and the content will be used in JD's new Dior ad campaign.

Johnny's got a long history with Dior ... he first signed with the company in 2015 as the face of the scent.