Rihanna was a teenager when her first single came out, and she looks like she hasn't aged a day.
Adam Levine is 40 years old, but he certainly doesn't look like it.
It's been 15 years since Kanye West released his first album, and he still looks the same.
In 2000, Beyoncé was 19 and in Destiny's Child. Today, she's 38 and still looking great.
Beyoncé's husband, Jay Z, also does not seem to age.
Twenty years ago, 17-year-old Mila Kunis was on "That '70s Show."
In 2000, Usher was 22, and he still looks like he's in his 20s.
At the start of the millennium, Will Smith was 21. In 2002, he was nominated for an Oscar after playing Muhammad Ali in a biopic.
Joseph Gordon-Levitt is almost 40 years old, but he doesn't look a day over 25.
Although Jamie Foxx is middle-aged, he still looks as young as he did in 2000.
Paul Rudd, now 50, is famous for his youthful looks.
Jennifer Lopez is 50 but looks like she's barely aged in the past 19 years.
Add a beard, and John Legend, 40, would essentially look like he did 13 years ago.
Actress Halle Berry is turning 53 this year.
Jared Leto doesn't look a day over 25. He's actually 47.
Mario Lopez is 46 but looks just as young as he did on "Saved by the Bell."
Sandra Bullock definitely doesn't look 55.
Singer Pharrell Williams, 46, is another celeb who never ages.
How could Eva Mendes look the same in two photos taken 16 years apart?
Aside from the salt-and-pepper beard, Idris Elba, 47, is unchanged.
William Shatner almost looks younger now than he did in the early 2000s. He's currently 88 years old.
Gabrielle Union is radiant at age 47.
Gwen Stefani was just 22 when her band No Doubt got a record deal. She's still performing today at age 50.
Jennifer Aniston, 50, might look even younger today than she did while starring on "Friends."
It's hard to believe that Elijah Wood is 38 years old.
Wood's "Lord of the Rings" castmate, Liv Tyler, has also barely aged. She's now 42.
Tyra Banks, now 46, looked the same over two decades ago.
Reese Witherspoon, 43, could still pass as her old character Elle Woods.
Christy Turlington rose to prominence as a supermodel in the 1980s. Today, she's 50 years old.
Rob Lowe, 55, has updated his hair color — but not much else has changed.
People love to lambast Gwyneth Paltrow's famously strict diet. Then again, maybe it's the secret to the 47-year-old's youthful glow.
It seems impossible, but "Full House" heartthrob John Stamos is 56 years old.
Lisa Bonet is 52, but looks essentially the same as she did 16 years ago.
Actor Taye Diggs made the leap from stage to screen but never seemed to age in the process. He's currently 48 years old.
Busy Philipps, 40, has barely changed since her "Freaks and Geeks" days.
Owen Wilson, 51, never lost his boyish looks.
Kate Winslet looks beautiful at 44.
If not for those few white beard hairs, it'd be tough to guess that Keanu Reeves is 55.
And Dame Helen Mirren is still effortlessly glamorous at 74.
Ricky Martin, 47, must be sipping from the fountain of youth.