Rob Lowe is celebrating his birthday with a trip down memory lane.

The actor, who turned 57 on Wednesday, celebrated his special day by sharing a side-by-side photo to Instagram featuring a current photo of himself, and a throwback picture from his days as a teen heartthrob.

"18th birthday on the set of The Outsiders," he wrote, indicating when the throwback image was from. "57th on the set of 911 Lonestar. In between have been amazing gifts professionally and personally."

Lowe starred as Sodapop Curtis in "The Outsiders" in 1983 and the movie has remained one of his best-known roles.

ROB LOWE STUNS CONAN O'BRIEN BY REVEALING FRIENDSHIP WITH THIS SUPREME COURT JUSTICE: 'WAIT, YOU KNOW HIM?'

These days, he’s starring in the Ryan Murphy-produced "9-1-1: Lone Star" as firefighter Owen Strand. The show is a spin-off of Fox’s popular "9-1-1."

Rob Lowe shared a throwback photo of himself on the set of 'The Outsiders' to celebrate his 57th birthday. (Photo by Presley Ann/FilmMagic/Getty)

In his Instagram caption, Lowe added: "I am a grateful man. Thank you for the birthday wishes. Means a lot. Love you all!"

TOM CRUISE WENT 'BALLISTIC' OVER SHARING ROOMS WHILE MAKING 'THE OUTSIDERS,' ROB LOWE CLAIMS

Fans wished the star a happy birthday in the comments of the post.

"Happiest of birthdays!" one person wrote. "More handsome at 57 than at 18 even!!!!"

CLICK HERE TO SIGN UP FOR OUR ENTERTAINMENT NEWSLETTER

"Happy birthday!! I love all of your work so much and hope you have an amazing day today!" said another. "Treat yourself today and have all of the ice cream that you would like!"

Left to right: Rob Lowe, C. Thomas Howell and Patrick Swayze on the set of 'The Outsiders.' (Photo by Nancy Moran/Sygma via Getty Images)

A third added: "The Outsiders is one of my ALL TIME FAVORITE movies! Happy birthday, have an awesome day!"