Clearly Shia LaBeouf is his own biggest fan.

The “Transformers” star is currently watching every single one of his movies — in reverse chronological order — as he hosts his own personal film festival in the Big Apple over three days.

As you read this, the 29-year-old actor is sitting in the Angelika Film Center in Soho partaking in a round-the-clock marathon — and he’s invited LaBeouf-loving New Yorkers to join him free of charge.

The performance-art project, which was announced Tuesday by his art collective, LaBeouf, Rönkkö & Turner, will highlight more than 15 years of his work, including some of his earliest and most iconic roles, such as Louis Stevens in “The Even Stevens Movie” and Stanley in “Holes.”

And out-of-towners need not worry — because the egotistical event, dubbed #AllMyMovies, is also being live-streamed on the project’s Web site, NewHive.

More On This...

LIVESTREAM: WATCH LABEOUF WATCH LABEOUF

The film fest kicked off Tuesday at noon with a showing of LaBeouf’s latest film, “Man Down.” The next movies up were “Fury,” “Nymphomaniac” volumes 1 and 2, “Charlie Countryman,” “The Company You Keep” and “Lawless.”

Sporting a thick beard and wearing a simple black T-shirt, LaBeouf was spied by The Post sitting in the fifth row of the theater in an aisle seat.

At one point during the showing of “Nymphomaniac: Volume 2,” he burst out laughing during the infamous restaurant scene, in which LaBeouf’s dinner date graphically uses spoons in a sexual manner.

“It’s unlike anything that I’ve experienced prior to this, getting to see how the actor reacts to his own films,” said Djordje Gasic as he walked out of the Angelika Film Center. “And it was rather interesting to see him and imagine what’s going through his mind — seeing himself on the big screen.”

The movie theater, which can seat up to 78 people, was packed throughout the day and there was a line of about 50-70 people waiting outside to get in.

“I think it’s a little psychotic that [LaBeouf] is watching his own movies nonstop for a few days,” said Emmeline Bone, a 24-year-old Bushwick resident who was waiting to go inside.

Isabel Bathencourt, a film student at NYU, had a more academic take.

“It seems kind of silly, [but] I’m trying to take it at face value,” she explained. “It is actually somewhat of an interesting idea to force yourself to watch yourself be other people for three days straight. But I think it’s also easily turned into kind of a spectacle. I mean, who knows why he’s doing it.”

This story first appeared in the NY Post.