The galaxy has an unexpected new Guardian, just in time for the holiday season.

Kevin Bacon, 64, made a surprise cameo last month in the trailer for “The Guardians of the Galaxy Holiday Special,” premiering Friday on Disney+. And while Marvel fanboys and fangirls were delighted by his casting, no one was more over the moon than Bacon himself. 

“Listen, I love to do that kind of stuff. To me, movies are this giant playground. I get to play and a grown man gets to just goof around and have fun,” Bacon, 64, recently told The Post. “I take the work very seriously, but in the case of something like ‘Guardians,’ you have to stop sometimes and go, ‘Oh, s- -t, this is really cool!’ I got a really, really fun gig.”

In the movie spinoff special, Mantis (Pom Klementieff) and Drax the Destroyer (Dave Bautista) set out to make Christmas a special one for Peter Quill (a k a Star-Lord, played by Chris Pratt) and find him the perfect present — by kidnapping and literally gifting Bacon to him (with help from a $40 Hollywood Star Map). 

But Bacon’s interstellar journey to the Guardians’ wild winter wonderland has been a strange one.

“Guardians” fans are well aware of Quill’s fixation on the “legend” of “great hero” Bacon, a delusion weirdly bolstered by the actor’s role in 1984’s “Footloose.” But his 2014 name-check in the “Guardians of the Galaxy” movie caught Bacon off-guard, so to speak.

“I was really shocked. I went to the movie without knowing that that’s what was going to happen,” Bacon recalled to The Post about venturing to a theater where it was showing. “And if you could imagine sitting there in a dark room with strangers — I was all alone — and all of a sudden they’re talking about me. I have pretty weird experiences in my life just based on, you know, what I do for a living. But that one was pretty weird.”

Ultimately, though, the proud Philadelphia native said he was “thrilled” by his “hilarious” inclusion — which made it even easier to sign on to filmmaker James Gunn’s new, festive frolic.

“He’s got a sort of left-of-center kind of point of view about the world, which I think was fascinating and interesting to me,” Bacon said of Gunn, with whom he worked on the action flick “Super” in 2010. “So when he reaches out and says, ‘I want to do this holiday special and you’re in it,’ that’s just an immediate, ‘Yes.’ I don’t need to read it. I’ll be there.”

But this is definitely not “Rudolph the Red-Nosed Reindeer,” “It’s a Wonderful Life” or whatever your grandma’s favorite, touching holiday classic may be.

For fans, the fast-paced, 44-minute show includes everyone’s favorite Guardians, including Quill, Drax, Mantis, Nebula (Karen Gillan), Groot (voiced by Vin Diesel), Rocket (voiced by Bradley Cooper), Kraglin (Sean Gunn) and Yondu Udonta (Michael Rooker). 

And it also features some subversive music, including a hilarious — and violent — Christmas carol, titled “I Don’t Know What Christmas Is (But Christmastime Is Here),” that entirely misconstrues the meaning of the holiday and labels Santa Claus “a furry freak.” It includes lyrics like: “Mrs. Claus, she works the pole / Plans her man’s demise / Soon the elves will all rise up and stab out Santa’s eyes.” (The 12-song soundtrack was released Nov. 23 and includes a tune with alt-country band the Old 97’s and vocals by Bacon, who since 1994 has performed alongside his sibling Michael in the group the Bacon Brothers.)

Interestingly, in December 2020, Bacon took to Facebook to declare himself “a bit of a Scrooge when it comes to Christmas music.” While he grudgingly saluted “Blue Christmas” by Elvis Presley, “Merry Christmas Baby” by Otis Redding and “Greensleeves” as performed by John Coltrane, he does otherwise bemoan the annual cacophony of Christmas carols.

“I think it’s maybe less the songs as the fact that they’re inescapable during that season, that every time you, you know, walk into a store or onto an elevator or turn on the radio, you know what I mean? You just can’t get away from it,” he told The Post. “But I think that one of the things that’s fun about the movie is, you know, down to James and his sense of humor — and also his musical taste is that he’s found a whole bunch of very cool holiday songs to stick in the movie.”

The “Apollo 13” star also is wishy-washy when asked for his all-time favorite holiday special before acknowledging his “love” for the original, animated version of Dr. Seuss’ “How the Grinch Stole Christmas.” It seems that one grabs his nostalgic heart.

“Part of why you like something like that is because it takes you back to when you first saw it, you know what I mean?” a reminiscing Bacon said. “So it’s not even so much about the content, the actual thing. It’s just that feeling of going back and experiencing what you experienced as a kid.”

Whether the “Guardians” special will become a prized perennial program remains to be seen — though Bacon may already be prepared for that extra notoriety, partly because of the pervasive Six Degrees of Kevin Bacon game. It claims that the “Friday the 13th” and “A Few Good Men” actor is the center of the entertainment universe and that any actor can be connected to Bacon — whose IMDb profile lists more than 100 roles — within just a half-dozen steps.

Bacon initially saw the game as a dig at his career and told The Post in 2013 that he “thought it would just kinda go away.” But he has since learned to accept the cultural quirk and even used it as a catapult for a nonprofit organization.

“It took me a while to see the value of that, frankly, but now I totally embrace it. It is my life,” as he most recently explained to The Post. “I don’t believe you become an actor because you want to hide. You become an actor because you want to do something that people are going to see and recognize. And sometimes that recognition comes in certain kinds of ways and sometimes that comes in other ways. 

“I’m just grateful that I get to keep working today, that I’m still able to do stuff that people still want to see. I pinch myself all the time.”