Party girls of the 2000s: Where are they now?

Girls just wanna have fun! Flashback to the early aughts when Paris Hilton and BFF Nicole Richie totally ruled the Hollywood club scene. Back then, the socialites-turned-reality stars rarely missed an opportunity to hit the town with their celebrity gal pals, including the likes of Kim Kardashian, Lindsay Lohan and even Britney Spears. But we all have to grow up at some point. In honor of Nicole's 36th birthday on Sept. 21, 2017, let's take a look at what she and other party girls of the 2000s are up to today.

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There's no denying that heiress Paris Hilton was one of the ultimate "It" girls of the 2000s. The model-socialite — pictured here in 2002 celebrating her 21st birthday at a posh New York City nightclub — made a name for herself on the party circuit. By the following year, Paris was fully in the national spotlight after a sex tape made with her then-boyfriend, Rick Salomon, was leaked and she nabbed a reality TV show with Nicole Richie, "The Simple Life." But she definitely got herself into some deep trouble with her luxe party lifestyle, getting a DUI in 2006, serving five days in jail for driving with a suspended license and copping a probation plea deal in 2010 after getting caught in Las Vegas with drugs in her purse.

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Paris Hilton is still quite the party girl at 36, but she's managed to keep herself in check and stay off the police's radar. She's also built a massive empire on her name that includes her own fashion line and a fragrance collection that's grossed over a billion dollars. Plus she's taken up a new career as a DJ — so she basically gets to club for a living — and is working on her second studio album following her 2006 self-titled debut. She's even sort of settled down with a gaggle of adorable pets at home, including a pack of pooches that have their own posh mansion doghouse, and a cute actor boyfriend, "The Leftovers" star Chris Zylka. The lovebirds have only been dating since the start of 2017, but Paris is confident that she's found the one. "I've never been surer of anything in my life," she told E! News in March.

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Nicole Richie grew up in the limelight: She was raised and formally adopted at the age of 9 by music legend Lionel Richie. In 2003, she became a household name when audiences got to know her as Paris Hilton's bestie and co-star on "The Simple Life," a reality show that documented the wealthy socialites as they comedically tried to fit into rural life in Arkansas. But her party-girl ways got her into a whole lot of trouble with the law during the 2000s: club brawls, driving without a license, possession of drugs and a DUI resulting in jail time (though she only served 82 minutes of her four-day sentence due to overcrowding).

Nicole Richie, who turns 36 on Sept. 21, 2017, has really cleaned up her act since those wild club days and run-ins with the law. Now a fashion designer, she's successfully expanded her House of Harlow 1960 jewelry brand to include shoes, handbags and apparel. Plus the former reality star proved that she's got some real acting chops thanks to her recent jump into the sitcom world with NBC's "Great News," which was renewed for a second season in 2017. Nicole's personal life is also smooth sailing these days: She's been with her hubby, Good Charlotte rocker Joel Madden, since 2006. They've got two adorable kiddos: Harlow and Sparrow.

Lindsay Lohan got her start in the movie biz at the age of 11 when she found fame with Disney's "The Parent Trap." She made it big in the 2000s with hit movies like "Mean Girls" and even topped the Billboard charts with her debut album, "Speak." But juggling such major success with a larger-than-life social agenda sent Lindsay down a slippery slope. The party girl racked up two DUIs, three stints in rehab and even jail time by the end of the decade.

It's taken Lindsay Lohan quite a while to get her life together, but she's seemingly on a better track these days. Following years of misdemeanor charges and probation violations, the 31 year old has avoided any more legal drama since completing a court-ordered, 90-day stint in rehab back in 2013. Afterward, she let the world in to watch her get back on her feet with a self-titled docu-series on Oprah Winfrey's OWN network. But she's still working to fully rebuild her reputation in the industry. More recently, Lindsay has been exploring her spirituality and traveling the globe (according to her Instagram pics) in the wake of calling off her engagement to Russian businessmen Egor Tarabasov in 2016. In January 2017, a rep for the star said that she "has been making positive changes in her life." And in March, she teased an upcoming fashion line.

Even though Kim Kardashian West isn't a big drinker, she still stepped out on the scene quite often back in the 2000s. She was first noticed alongside pal Paris Hilton, for whom she worked as a stylist-assistant, but became pretty well-known on her own after a sex tape she'd made with former boyfriend Ray J surfaced in early 2007. After amassing a ton of fans with her family's 2007 reality show, "Keeping Up with the Kardashians," Kim made her party lifestyle into a business, getting booked left and right for big-paying club appearances.

Nowadays, 36-year-old Kim Kardashian West has much bigger fish to fry than club appearances! She's created a billion-dollar brand out of her name with everything from fragrances to game apps and even her own set of emojis, dubbed Kimojis. In June 2017, she raked in $14 million in a mere three hours with the sell-out launch of her KKW beauty line. She also has a fashion line with her sisters, Kourtney Kardashian and Khloe Kardashian, and launched a Kardashian Kids collection. In 2016, Forbes estimated that Kim earned a whopping $51 million between all of her ventures. But the mogul was terribly shaken after being robbed at gunpoint in her Paris hotel room the same year. She opted to take a step back — even from her 103 million Instagram followers — to focus on what matters the most to her: family. Kim married rapper Kanye West in 2014, and they now share daughter North and son Saint. They're reportedly expecting their third child via surrogate in early 2018.

Let's be real: Tara Reid was a bit of hot mess in the early aughts. The "American Pie" star became a total party animal after her engagement to "TRL" host Carson Daly ended in 2001. She stayed in the headlines with a couple of botched plastic surgeries and some pretty unusual behavior — like posing for photos with her breast fully exposed at Diddy's birthday party in 2004.

Now in her early 40s, Tara Reid has clearly gotten better at choosing which parts of her skin to show off, but she definitely still has a wild side, especially when it comes to her personal life. In 2016, she got caught faking a relationship with Dean May just to get onto VH1's "Marriage Boot Camp: Reality Stars." And before that, she admitted that her 2011 marriage to financier Zack Kehayov wasn't real. Her career, on the other hand, hasn't been as all over the place. Since starring in the original "Sharknado" in 2013, Tara's been in all four of the Syfy network's horror comedy franchise sequels. And she recently worked on a passion project, a movie called "Worthless," which takes aim at bullying and body shaming.

Nicky Hilton was almost always along for the ride with big sister Paris Hilton, and boy, did the socialite siblings take the Hollywood party scene by storm back in the aughts. But unlike Paris, Nicky tended to stay out of trouble. She did, however, have a quickie Las Vegas wedding annulled in 2004.

Nicky Hilton Rothschild, 33, is a party girl no more. In fact, she's very busy being a new mom and even has her second on the way! In 2016, Nicky welcomed daughter Lily Grace Victoria with her financier husband, James Rothschild. The lovebirds, who started dating in 2011, announced that they were expecting again in June 2017. It makes perfect sense that Nicky, also a successful fashion designer, is prepping to launch a collection dubbed Mommy +Me with Tolani in 2018. She's also created collections for eLuxe and launched her own brand, Nicholai.

The 2000s were a whirlwind of ups and downs for Britney Spears, and her partying got a little bit out of control in the process. In between releasing chart-topping albums like "Oops!… I Did It Again" and "In the Zone," she struggled with a lot of personal issues — a breakup with Justin Timberlake, a failed marriage to Kevin Federline, a nasty custody battle over their kids, rehab and serious psychiatric issues. It all culminated with a public meltdown in 2007.

Fortunately, Britney Spears got help for her mental health issues and is totally back to being her usual superstar self these days. The 35 year old released her ninth studio album, "Glory," in 2016, and has been slaying her "Piece of Me" Las Vegas residency for close to four years, though she's set to wrap it up at the end of 2017. And her two boys from her marriage to Kevin Federline are growing up so fast: Preston is 12 and Jayden is 11. Britney is also happy in love! She's in an adorable relationship with a younger man, 23-year-old fitness model Sam Asghari.

With a dad like rocker Ozzy Osbourne, Kelly Osbourne's life was never average. She grew up in the spotlight, featured on the family's MTV reality TV show, "The Osbournes," and made a go at the music industry herself with her 2002 debut album, "Shut Up." But living the good life and partying hard at a young age caught up to Kelly, who was in and out of rehab for half of the aughts.

Kelly Osbourne, 32, has seemingly ditched all of her teenage angst and traded it in for a career in TV and fashion. She's been a correspondent for E!, covering major awards shows for the network, and was a host on "Fashion Police" until her exit in 2015 following a feud with co-host Giuliana Rancic. In 2017, she released a tell-all book, "There Is No F—ing Secret: Letters From a Bad–s B—-," in which she shares some pretty shocking stories from her youth, and has been very open about her recent struggle with Lyme disease. Her love life is seemingly quiet these days, but the same can't be said for her famous parents, Sharon Osbourne and Ozzy Osbourne. In 2016 after her dad was caught cheating, Kelly took it upon herself to out his mistress by tweeting her phone number!

Disney Channel star Hilary Duff played good girl Lizzie McGuire on TV in the 2000s, but off-camera, the party girl was also growing up pretty fast. Drama surrounding her public relationships with the likes of Aaron Carter and Joel Madden put all eyes on Hilary. Despite knowing how to have a good time with her friends, she was still able to expand her career onto the big screen with movies like 2003's "Cheaper by the Dozen" and broke into the music scene with a 2004 self-titled debut album.

Hilary Duff's social calendar got a bit more mellow when she married professional hockey player Mike Comrie in 2010. Though they separated four years later, the exes have been a great example of how to amicably co-parent (son Luca is 5). Hilary, now 29, has had an eventful love life in the last year, having dated and split from both trainer Jason Walsh and music producer Matthew Koma. She was last linked to businessman Ely Sandvik in July 2017. These days, she's sitting pretty as one of the stars of the hit TV Land sitcom "Younger," which was recently renewed for a fifth season. In May 2017, she added to her little fam with an adorable new puppy.

As part of the ensemble cast on FOX's "The O.C." from 2002 to 2007, Mischa Barton was thrust into the Hollywood scene with all of her co-star friends. But it was all a bit too much for the young actress, who ended up with a DUI and was placed on a short, involuntary psychiatric hold toward the end of the aughts.

Mischa Barton had seemingly taken care of her mental health issues and stepped back into the spotlight with a stint on ABC's "Dancing with the Stars" in 2016, though she was eliminated early on. She followed up with roles in smaller movies like "The Hoarder" and "Deserted." But in early 2017, she was again taken to a Los Angeles hospital for a psych evaluation after neighbors spotted her acting erratically outside of her home. Around the same time, news emerged that her ex-boyfriend was shopping a reportedly doctored sex tape of her, possibly adding to her distress. She described the situation to Dr. Phil as "emotional blackmail." Now, things are looking back up for Mischa, who was romantically linked to Australian model James Abercrombie in July 2017.