THEN AND NOW: 10 of the biggest child star transformations

"Hannah Montana" quickly became one of the most popular Disney shows of all time, and Cyrus, by extension, became a huge star. During her time on the show, she recorded six albums as Hannah Montana, three albums as herself, and starred in two films.

After ending her reign on the Disney Channel, Cyrus, now 28, went through a bit of a wild-child phase. She tried out hip-hop/rap for "Bangerz," trippy LSD-friendly anthems for "Dead Petz," came all the way back around to country for "Younger Now," and currently seems to be engaging in an '80s/'90s rock look for her upcoming album "Plastic Hearts."

Along the way, she also got married and divorced, came out at bisexual, hosted the VMAs, founded the Happy Hippie Foundation, and became the queen of covers.

Thorne began starring on "Shake It Up" in 2010 alongside Zendaya. Prior to that, she had also appeared in films like "Blind Ambition" and "Stuck On You," as well as TV shows like "Dirty Sexy Money," "October Road," and "Big Love."

"Shake It Up" ended in 2013. Right after that, she continued to appear in mainstream films such as "Blended" and "The DUFF."

Thorne, 23, still acts and sings, but that's not what she's really famous for anymore. Besides her relationships with Tyler Posey, Charlie Puth, Tana Mongeau, and ModSun, Thorne has become well-known in the adult film industry. She made her directorial debut on PornHub in 2019 with the adult film "Her & Him," which won her the Visionary Award at the 2nd Pornhub Awards.

In August 2020, she earned $1 million in 24 hours after joining the subscription-based app "OnlyFans," which lets creators post exclusive content behind a paywall.

In order to play the lovably nerdy Longbottom, Lewis "had to wear a fat suit and false teeth and stuff to stick my ears out," he told The Big Issue.

As Urban Dictionary puts it, Longbottoming is "the sometimes slow, sometimes overnight, always surprising transformation of someone, usually a man, from decidedly unattractive to hot as hell a la Matthew Lewis, the actor who played Neville Longbottom in the 'Harry Potter' film series."

For '80s teens, there was no one more relatable than Hall's characters. But even in the '80s, he was nervous about getting typecast as a nerd, which led to his one-season stint on "Saturday Night Live," and his characters in "Johnny Be Good" (a football star), "Edward Scissorhands" (a macho jealous boyfriend), and "Into the Sun" (a conceited actor learning about the Air Force).

In his later career, he's buzzed off his hair and taken roles playing law enforcement, including Johnny in "The Dead Zone," a man who wakes from a coma to realize he can communicate with the dead, an ability he uses to solve crimes.

He also leans into '80s nostalgia — he played the villainous Principal Featherhead in "Riverdale" and is set to appear in the upcoming "Halloween" sequel.

O'Connell's character was mainly comic relief in "Stand By Me." While he was a big part of the film, he didn't achieve real mainstream success until he began starring in "Sliders," which aired from 1995 to 1999.

O'Connell, now 46, hosts his own syndicated talk show ("Jerry O'"), voices a role in "Star Trek: Lower Decks," and stars in the Canadian show "Carter."

Since 2007, he's been married to Rebecca Romijn.

Winter was just 11 years old when she began appearing on "Modern Family" as Alex, the nerdier and more sarcastic sibling in the Dunphy clan.

Winter remained on "Modern Family" during all 11 seasons, while also doing voice work for "Sofia the First," "Robot Chicken," "Mr. Peabody and Sherman," and "Smurfs: The Lost Village," among others.

In 2015, the 23-year-old announced she had legally emancipated from her mother.

Urkel was only supposed to be on "Family Matters" for one episode, but his popularity and hilarious performance made that impossible. In fact, he was so popular he appeared on other '80s and '90s sit-coms like "Full House," and "Step By Step," and was mentioned by name in "Boy Meets World."

Now, Urkel is probably the most well-remembered character from the show.

White, 43, still acts. Shortly after "Family Matters" ended, White told a reporter, "If you ever see me do that character again, take me out and put a bullet in my head and put me out of my misery.''

And he didn't play Urkel again for almost 30 years — he reprised the role in 2019 to voice him in an episode of "Scooby Doo and Guess Who?"

They were best friends in the show, but Kevin and Paul grew apart. Paul was shown to be extremely smart, and the finale revealed that Paul attended Harvard and became a lawyer.

"The Wonder Years" was Saviano's first role, and during the show he didn't do much other acting. One of his only other credits is the 1990 TV movie "Camp Cucamonga."

Much like Paul, Saviano, 44, attended an Ivy League school (Yale, not Harvard), and became a lawyer. "The Wonder Years" was his first and last big role.

After a 21-year break, Saviano returned to acting for a three-episode stint on "Law & Order: SVU" as, you guessed it, a lawyer named Don Taft.

Saviano and and his "Wonder Years" co-star Fred Savage are still friends today, as seen on Instagram.

When Green was cast in "90210," he was younger than the rest of his co-stars, and he looked it. He was shorter than Ian Ziering, who played Steve, by a full head, and it made perfect sense that he had this unrequited love for Donna, played by Tori Spelling.

But as the show went on, Green grew up. Eventually, he was almost unrecognizable from his season-one self.

Green has continued to act, mainly on TV. He's had roles in "Happy Endings," "Smallville," "Terminator: The Sarah Connor Chronicles," "Desperate Housewives," and played himself in "BH90210."

After getting eliminated from "The Masked Singer," Green was named as a judge for the upcoming spin-off, "The Masked Dancer."

In 2020, he and his wife Megan Fox announced they were divorcing after 10 years of marriage.

Raven, as she's also known mononymously, has pretty consistently been on our TV screens ever since. After "Hangin' with Mr. Cooper" ended in 1997, she appeared in "Zenon: Girl of the 21st Century" in 1999, in "Kim Possible" from 2002 to 2007, and, most famously, "That's So Raven," from 2003 to 2007.

In 2003 and 2004, she also appeared in "The Cheetah Girls" and "The Princess Diaries 2: Royal Engagement." She also found time to release four albums from 1993 to 2008.

The 34-year-old took a bit of a break from acting in the 2010s, but she was still around — she hosted "The View" from 2015 to 2016, and appeared as herself on various talk shows. Since 2017, she has starred in and executive produces "Raven's Home," a spin-off of her original Disney show that focuses on her and her twin children.

In 2020, she married Miranda Maday, a social media manager.

• Read more:
• THEN AND NOW: The biggest celebrity transformations of the past decade
• THEN AND NOW: Here's what all your favorite '90s actors are doing today
• WHERE ARE THEY NOW: The biggest child stars of the '80s
• 13 child stars who quit Hollywood for good