Turns out Evan Peters’ Tree Hill roots run deep.

In fact, the American Horror Story alum recently had a special reunion with his One Tree Hill costars, including Sophia Bush, Ashley Rickards and Austin Nichols, 15 years after he appeared as Jack Daniels on the show.

In a Sept. 24 post to her Instagram story, Sophia (who played Brooke Davis) shared a picture of the group ahead of an event for Friends With Benefits Charity Events, an organization that held a cast reunion event called 21 Tree Hill centered around the 21st anniversary of the CW show’s 2001 premiere.

In the photo, Evan (who starred for six episodes in the show’s sixth season) wore a plain white tee and brown pants while smiling alongside Sophia, who wore a sleek black pantsuit and T-shirt that read, “I [heart] Ambitious Women.” Ashley (who played Sam Walker, Jack’s best friend) also joined in for a group photo, clad in a white tee and gray, flared jeans, next to Austin (Julian Baker), who sported an all-black ‘fit including a short-sleeved T-shirt and straight-leg jeans.  

It wasn’t the only One Tree Hill celebration over the weekend. Sophia also shared pics from a birthday party for fellow Tree Hill Raven Bevin Prince where many of the show’s cast—including James Lafferty, Bethany Joy Lenz and Lee Norris—were in attendance. On a group photo, she wrote, “21 Years,” with a heart and teary-eyed emojis.

And while Evan’s reunion certainly marks a special occasion, some of the cast is planning even more get togethers in the future. After all, news broke three weeks ago that a One Tree Hill sequel is in the works at Netflix with Sophia and Hilarie Burton reportedly returning to star.

“The sequel is said to take place 20 years later,” according to Deadline, “following best friends Brooke and Peyton who are now parents to teens and facing challenges not unfamiliar to what they tackled in the original series like love, insecurities and grief.”

The show will reportedly be executive produced by Sophia, Hilarie and fellow alum Danneel Ackles, as well as Parenthood producer Becky Hartman-Edwards, who is working on the script, per Variety.

Read on to see more One Tree Hill cast reunions over the years.

Sophia Bush, Hilarie Burton, Danneel Ackles, Bevin Prince, Stephen Colletti, Austin Nichols, Matt Barr and more stars ofreunited for a 20th anniversary celebration thrown by FWB Charity Events in November 2023.

"Got to hang out with some great humans this weekend," Austin wrote in November 2023. "Old friends. Old stories. Lots of laughs. And made a bunch of new friends. Thank you to everyone who made this happen!"

Michael Trucco and James Lafferty photoshopped a sign to pay tribute to the show. "Sign seems legit," Michael wrote. "Always a good day when I get to spend time catching up with my buddy/nephew."

James Lafferty and Bryan Greenberg had a mini One Tree Hill reunion and were joined by Jamie Chung and Alexandra Park.

As Hilarie shared, these three will always be there for another, through "thick and thin."

Fans were loving this reunion, including Kristin Cavallari, who commented a heart on the post.

Hilarie and Robert give the camera a cheeky look in this selfie.

It's safe to say these former cast mates will be BFFs.

Clearly, someone cannot contain their excitement over this reunion. 

Throughout the many seasons of One Tree Hill, fans got to know and love many a character, including Michael Trucco's Cooper. As die-hard fans will recall, the conniving Rachel seduced Cooper and tricked him into thinking she was having his baby in the second season. The gig was up, however, when they both got in a car accident and she had to confess she lied about the whole thing, thus leading to Cooper's exit. 

Hilarie poses with the famous Angel of Death character that used to plague her. 

For the latest breaking news updates, click here to download the E! News App