Jennifer Aniston
21-year-old Jennifer made an appearance on the "Ferris Bueller" TV show; by 30, she was well past the "Rachel" haircut days and now showing up to award shows on the arms of Brad Pitt.
(Courtesy/Getty)
Jessica Simpson, 31
In 2000, when Jessica was 20, her album <em>Sweet Kisses </em>had gone double platinum. In 2010, when Jess turned 30, she announced her engagement to football player Eric Johnson.
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Beyonce Knowles, 30
In 2001 at the age of 20, Beyonce made her film debut in "Carmen: A Hip Hopera." By 2011, when Bey turned 30, she had released her fourth solo album and was pregnant with her first child.
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Katie Holmes, 33
In 1998, 20-year-old Katie Holmes was casted as Joey Potter on "Dawson Creek." In 2008, at age 30, Katie started a high fashion clothing line called Holmes & Yang with stylist Jeanne Yang.
(Getty photos)
Gwyneth Paltrow, 39
In 1991, 19-year-old Gwyneth had already made her stage debut and starred that year as Wendy Darling in "Hook." In 2002, at age 30, Gwynnie met her future husband Chris Martin.
(Hulton Archive/Getty)
Christina Aguilera, 31
In 2000, 20-year-old Christina released her first Spanish album <em>Mi Reflejo.</em> At the age of 30, in 2010, Xtina earned a Golden Globe nomination for Best Original Song for the movie "Burlesque."
(Getty/AFP)
Britney Spears, 30
In 2001, at the age of 20, Britney had already released her third album, <em>Britney</em>. In 2011, 30-year-old Brit had been awarded the MTV Video Vanguard Award from Lady Gaga, who said that "industry wouldn't be the same without [her]".
(Getty photo)
Claire Danes, 33
In 1999, 20-year-old Claire appeared in two films: "The Mod Squad" and "Brokedown Palace." In 2009, at 30 years old, Claire married Hugh Dancy in private ceremony in France.
(Getty/AFP photos)
Drew Barrymore, 37
In 1995, a 20-year-old Drew showed her breasts to David Letterman while on his show. When Drew turned 30 in 2005, she was the subject of the documentary "My Date with Drew."
(AFP/Getty photos)
Natalie Portman
In 2001, when Natalie turned 20, she was nominated for a Young Artist Award for her role in "Where The Heart Is." In 2011, 30-year-old Natalie, who's now a mom, won a Golden Globe and Academy Award for her performance in "Black Swan" and has gone from cute kid to glamour girl.
(Getty photos)
Julia Stiles, 31
In 2001, a 20-year-old Julia stared in the very successful "Save The Last Dance." In 2011, at 30-years-old, Julia started playing Jeannie in a production of Neil LaBute's "Fat Pig."
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Jessica Biel, 30
In 2002, "Seventh Heaven" star Jessica Biel was known for her beauty and tomboy style. Now at the age of 30, Jessica's gone brunette and of course, is engaged to Justin Timberlake.
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Nicole Richie, 30
In 2001, at the age of 20, Nicole was rocking the grungy rocker girl look. By the time she turned 30 in 2011, Richie transformed herself into one of the most stylish celebs and fashion entrepreneurs in the business.
(WireImage/Getty photos)
Tyra Banks, 38
In 1993, at age 20, Tyra was one of the most popular models in the industry. In 2003, a 30-year-old Tyra created the hit show "America's Next Top Model."
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Jessica Alba, 31
In 2001, at the age of 20, Alba was nominated for her role in "Dark Angel." In 2011, 30-year-old Jessica had traded in the '90s lipstick and gave birth to her second daughter, Haven Garner Warren.
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Alexis Bledel, 30
At the age of 20, Bledel was known as girl-next-door Rory Gilmore on the hit show "Gilmore Girls." In 2011, at the age of 30, Alexis was better known for her awesome fashion sense and film career.
(WireImage/Getty photos)
Michelle Williams, 31
In 2000, at the age of 20, Williams was known for her roles on "Dawson's Creek" and in independent films. By 2010, 30-year-old Michelle was (and still is) considered one of the most stylish and talented actresses of our time.
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Sarah Michelle Gellar, 35
At the age of 20, Gellar was one of the biggest television stars of her generation. In 2007, when she turned 30, Sarah Michelle became the face of Maybelline.
(Getty photo)
The Huffington Post | By Michelle Manetti & Jessica Misener Posted: 05/16/2012 4:28 pm Updated: 05/16/2012 6:12 pm