Katie Holmes posed up backstage at her Broadway play Our Town with a tall, bearded co-star, who happens to be a major television actor.

The cozy selfie was uploaded to Holmes’ Instagram on Thursday, with fans flocking to the comments to remark on her co-star’s ‘unrecognizable’ appearance.

He famously starred as child prodigy-turned-genius physicist on a beloved multi-camera sitcom by Two And A Half Men creator Chuck Lorre.

The half-hour comedy premiered back in 2007 and ran for 12 seasons on one of American TV’s Big 4 networks.

The actor’s performance on the show earned him four Emmy Awards and a Golden Globe for Best Performance by an Actor in a Television Series – Comedy or Musical.

But can you guess who Katie’s Our Town co-star is?

Katie Holmes posed up backstage at her Broadway play Our Town with a tall, bearded co-star, who happens to be a major television actor

The cozy selfie was uploaded to Holmes’ Instagram on Thursday, with fans flocking to the comments to remark on her co-star’s ‘unrecognizable’ appearance

It’s Jim Parsons, who played Sheldon Cooper on CBS’ The Big Bang Theory.

The revival of Thornton Wilder’s Pulitzer Prize-winning play, which was first performed in 1938, officially returned to Broadway in October after weeks of previews that started on September 17.

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Narrated by a stage manager, the meta play revolves around New Hampshire village life at the dawn of the 20th century.

Amid a Spartan stage set, characters break the fourth wall, travel backwards in time and even return from beyond the grave.

Along with Holmes and Parsons, the revival features performances from Zoey Deutch, Ephraim Sykes, Julie Halston, Richard Thomas and Michelle Wilson.

Holmes stars as Mrs. Webb, mother to Deutsch’s protagonist Emily, while Parsons leads the show as the Stage Manager.

Our Town officially closes on Broadway after its matinee show on Sunday, January 19. 

And with the play’s three month run at the historic Ethel Barrymore Theatre coming to a close, Holmes took to Instagram on Thursday to pay homage to the cast and Parsons, who she’s grown extremely close to.

The unrecognizable actor is Jim Parsons, who played Sheldon Cooper on CBS’ The Big Bang Theory

Parsons and Holmes star together in the revival of Thornton Wilder’s Pulitzer Prize-winning play, which officially returned to Broadway in October after weeks of previews; (L-R) Jim Parsons, Zoey Deutch, Katie Holmes and Richard Thomas pictured on opening night in October

With the play’s Broadway run coming to a close on January 19, Holmes took to Instagram on Thursday to pay homage to the cast and Parsons, who she’s grown extremely close to

She shared a pH๏τo of Parsons, donning a black hat and coat, wrapping his arms around her as she leaned in close to him with a smile on her face.

‘The final days of @ourtownbroadway are upon us,’ the Dawson’s Creek alum began.

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‘I am so grateful for these beautiful souls that continue to bring Thornton’s words to life. I love you @therealjimparsons.’

Like Parsons, Holmes is all too familiar with what it’s like starring on a hit TV show.

She famously played Joey Potter on the teen drama Dawson’s Creek from 1998 to 2003 on The WB.

And fans were thrilled to see two ‘iconic’ TV stars posing for a pH๏τo together.

‘Two amazing actors and two of the most iconic tv series characters to me,’ commented one fan, who also left two red heart emojis.

Another wrote: ‘Joey and Sheldon… never saw that coming, but I loved it’

‘I love you @therealjimparsons,’ Holmes gushed in the caption of her Instagram post; the co-stars seen on January 7

Fans were thrilled to see two ‘iconic’ TV stars posing for a pH๏τo together

Others remarked on how ‘amazing’ the duo looked as they expressed their ‘love’ for the ‘brilliant’ revival

Others remarked on how ‘amazing’ the duo looked as they expressed their ‘love’ for the ‘brilliant’ revival.

Holmes’ time at Broadway’s Our Town came weeks after she saw her daughter Suri Cruise, 18, off to college.

The teenager — whom Holmes shares with ex-husband Tom Cruise — is a freshman at Carnegie Mellon University in Pennsylvania.

Suri returned home to NYC during winter break and even stopped by the Ethel Barrymore Theatre to hang out with the Our Town cast.

Over the summer, Holmes gushed to Town & Country about how ‘proud’ she is of her only child and that she’ll miss not having her at home.

‘I’m proud of my daughter. Of course, I will miss the close proximity, but I’m really proud of her and I’m happy,’ the TV star gushed.

‘I remember being this age, this time of beginnings. It’s exciting to learn about yourself, and I loved that time, so it makes me happy to think about it like that.’ 

Katie divorced Suri’s dad Tom in 2012 and the teen is believed to be estranged from the 62-year-old Top Gun star.