There are tons of celebs and pop stars who became friends because of their fame, or in spite of it. But there are also several pals who were in each other's lives before they made it big. They met on their way up the ladder of fame.

Check out our list of famous pre-fame besties and bros, like Madonna and 'Entourage' star Debi Mazur, who linked up when both were struggling in NYC and remain pals to this day. Then there are former Mouseketeers Britney Spears and Christina Aguilera, who started out as buddies but eventually grew apart and became pop rivals, maintaining a cool respect for one another.

There are many more sets of pre-fame pals, each with their own set of circumstances. See 'em here.

  • 1

    Demi Lovato and Selena Gomez

    The dark-haired, future Disney gals both appeared on 'Barney and Friends' when they were adorbs little tykes. The cutie pies appeared on the purple dinosaur series in the seventh and eight seasons, from the years 2002 through 2004. See 'em here. #TooCute. They remain as gorgeous and as friendly as ever.

    Jason Merritt, Getty Images
  • 2

    Madonna and Debi Mazur

    Her Madgesty and Mazur met in the elevator of NYC's Danceteria! Talk about total chance and happenstance. Mazur, then a struggling makeup artist, took on Madge, then a struggling pop star, as a client and the rest is herstory. The pop diva and the actress, who appeared on 'Entourage,' in addition to 'Goodfellas,' among others, remain BFFs to this day. Mazur, who appeared in plenty of Madge's videos, once hinted that former hubby Sean Penn was Madonna's true love.

    Jason Merritt (2), Getty Images
  • 3

    Britney Spears and Christina Aguilera

    Brit Brit and Xtina? They were BFFs during their days as Mouseketeers on 'The Mickey Mouse Club.' They grew up, grew apart and were eventually rivals clamoring for pop diva dominance, which was said to be a media-fueled thing. But hey, they both made out with Madonna. They consider themselves friends nowadays, but it's more like a cool respect than it is BFFdom.

    Jason Kempin / Valerie Macon, Getty Images
  • 4

    Leonardo DiCaprio and Tobey Maguire

    The handsome and talented actors met on the job – at an audition years ago, with DiCaprio saying that he just knew that he wanted to befriend Maguire. They're still buddies and recently appeared as close friends Jay Gatsby and Nick Carraway in the latest big screen adaptation of 'The Great Gatsby.'

    Didier Baverel / Lisa Maree Williams, Getty Images
  • 5

    Gwyneth Paltrow and Maya Rudolph

    The lovely and talented actresses go way, way back. Their fathers, Bruce Paltrow and Dick Rudolph, respectively, were friends in college, so it was inevitable that their little girls would connect. They went to the same school and were pals since the age of 7.

    Jason Merritt / Frazer Harrison, Getty Images
  • 6

    Jessica Chastain and Michelle Williams

    These two celebrated, Oscar-nominated actresses lived together in leaner times. While Williams was on 'Dawson's Creek,' they both starred in a production of 'The Cherry Orchard,' shacking up. Little did they know...

    Alberto E. Rodriguez / Craig Barrit, Getty Images
  • 7

    Matt Damon and Ben Affleck

    This duo has been pals since childhood, as they both grew up in Massachusetts. You know the drill -- they eventually went on to win Oscars for Best Original Screenplay for writing 'Good Will Hunting.' Of course, they also became the subject of a famed Jimmy Kimmel and Sarah Silverman skit about f--king Matt Damon and Ben Affleck, respectively.

    Ethan Miller, Getty Images
  • 8

    Paris Hilton and Nicole Richie

    This blonde twosome was best friends since childhood, but they got stratospherically famous together by starring in their 'The Simple Life' reality series. Plenty of late nights, arrests and fashion copycats arose, and the ladies eventually fell out. But not before they achieved crazy levels of fame.

    Kevin Winter, Getty Images
  • 9

    Katy Perry and Robert Pattinson

    Okay, we're sort of cheating with this one, since both the pop singer and the actor were on the rocket ride to fame when they filmed this karaoke video. Their careers were starting to take off at this point, but it was the tip of the iceberg, so we can call it pre-MAJOR fame friendship. They remain buddies who can fart in front of one another.

    David Becker / David Livingston, Getty Images
  • 10

    Lindsay Lohan and Raven Symone

    The actresses (and singers) met on the set of a photo shoot and became pals. They had a "roommate experience," with Symone saying Lohan was cool, but got super busy with work. So despite dropping off her clothes and shoes, she never officially moved in. She did pay rent, though.

    Jason Merritt / Neilson Barnard, Getty Images