HOLLYWOOD hottie Amber Heard flipped for fiancé Johnny Depp long before they ever crossed paths!

“Johnny was Amber’s first love, even though she’d never met him,” a pal of the 28-year-old beauty told The ENQUIRER.

“When she was a teenager, Amber had al­ready decided to become an actress and she had pictures of Johnny all over her room.

“So it’s no surprise they fell in love while working to­gether. Amber can usually get whatever she sets her mind to.”

Like her husband-to-be, Am­ber dropped out of high school, leaving St. Michael’s Catholic Academy, a private school in Austin, Texas, at age 17.

But while she was there, the “3 Days to Kill” star made a big im­pression on her classmates.

Amber was very quiet, so some people used to call her ‘Am­ber seen and not Heard,’” recalled classmate Meghan Brindley.

“She always seemed almost like her mind was just off somewhere else. She always said, ‘I’m going to go and be an actress and that is what I want to do.’”

The leggy beauty fell in love with Depp, 50, while the two filmed “The Rum Diary” in 2009. They didn’t go public with their ro­mance until after Depp ended his 14-year relationship with French model/singer Vanessa Paradis, mother of his children, Lily-Rose, 14, and Jack 12.

By then, bisexual Amber had dumped her lesbian lover, 37-year-old photographer Tasya van Ree, for the “Pirates of the Caribbean” star.

As The ENQUIRER has reported, Amber and Depp plan to tie the knot this summer. But the relationship may be headed for di­saster over their nearly 23-year age difference and Amber’s lingering affections for Tasya. And Johnny’s ex-lover Vanessa isn’t making things any easier. Sources say she’s trying to drive Johnny crazy by recently showing off her fabulous figure in a sexy photo shoot – and he took notice, seeing her “in a totally different light.”

MEANWHILE, Amber seems to be getting g the jitters – she was photographed looking ex­tremely distressed while sitting in a car on the day before their lavish engagement party.

Still, wedding plans are in full swing – evi­dent by Johnny flashing a diamond ring on HIS finger.

“The fact that I’m wearing a chick’s ring on my finger is probably a dead giveaway,” he said. “Not very subtle.”