He’s going back to his roots. 

Fresh off of finishing his eight-season stint starring on “Outlander,” Sam Heughan will star as Macbeth onstage in London for the Royal Shakespeare Company. 

“We start rehearsing next week. Hence my dodgy beard and hair,” Heughan, 45, exclusively told The Post. 

The play runs Oct. 9 through Dec. 6. 

“I’m very excited to be doing ‘Macbeth’ at the RSC, Stratford-upon-Avon and the birthplace of Shakespeare. And it’s going to be an amazing journey, really full circle for me. It’s where I started, in theater,” he said, referring to his career before he rose to fame when “Outlander” premiered in 2014. 

For eight seasons, Heughan starred in the time-traveling Starz historical romance as Jamie Fraser. The show follows Claire (Caitriona Balfe), an English nurse who time-travels from 1945 to the 1700s, where she meets Jamie.

The show will end with Season 8, premiering at an unannounced date in 2026. So, although the ending hasn’t aired yet, Heughan is finished playing Jamie.

Now, he’s stepping into the shoes of one of Shakespeare’s most famous characters.

“It’s been a long time since I’ve been onstage. So, you know, there’s a lot of trepidation but also excitement. I can’t wait to get started,” the Scottish actor said while promoting his book, “The Cocktail Diaries: A Spirited Adventure,” out Sept. 23.

When asked if he’s conceptualized a “Macbeth”-themed cocktail for his new role, he said, “Yeah, we have been talking about it. I’ve actually been talking about, like, what kind of gin would Lady Macbeth have? She talks about having drunk something, and there was actually a mention of a number of botanicals in the play.” 

“Who knows, maybe we’ll see a Macbeth spirit coming soon. ‘Spirit’ being the pun.” Heughan has an alcohol brand, Sassenach Spirits.

The “Outlander” world has also expanded into the prequel series, “Outlander: Blood of My Blood,” following the lives of Jamie and Claire’s parents (Jamie’s parents are played by Jamie Roy and Harriet Slater, while Claire’s are played by Hermione Corfield and Jeremy Irvine). 

About his on-screen father, Roy, Heughan said, “He’s an extremely talented actor, a really lovely guy. And we got on very well.”

“We’ve hung out a bit since [meeting],” he continued. “He’s super driven and hardworking, and I couldn’t think of anyone better to take over the role.” 

Since “Outlander: Blood of My Blood” follows Jamie’s parents before he was born, Heughan isn’t in the show. But, it does involve time travel. So, could he ever make an appearance? 

“Look, never say never,” said Heughan.

“But also, we all know Jamie Fraser can’t time-travel,” he pointed out, as Claire is the one who is sent flying through time.

“So I don’t know. You’d have to do some really weird stuff because he’s not been born yet. But, who knows?”