Shia LaBeouf Has Tense Moment With Obnoxious Fans at Cannes, on Camera

Shia LaBeouf has truly turned a new leaf ... 'cause the dude showed a lot of patience with some obnoxious fans who would not leave him alone as the actor walked along a boulevard in Cannes, France.

Here's the deal ... the Hollywood star -- known as much for his stellar acting as his bad boy behavior -- played it super cool Sunday night when a few overzealous dudes would not back off for a picture.

As you can see for yourself, Shia is hounded by a small group of fans ... and a couple in particular wouldn't stop pestering him -- even after already snapping a few with SL!

It's pretty clear by Shia's face he is over one dude in particular, fast ... and then he calmly -- but sternly -- tells the guys to back the F off.

It's pretty commendable since in the past, the actor very well may have snapped ... and then the real trouble would have started.

Shia is in Cannes for a kinda shocking reason ... to support the doc "Slauson Rec," which is a hardcore, unforgiving look at the rise and fall of the theater company LaBeouf launched in Los Angeles in 2018.

Footage reportedly shows moments of SL in a rage and being super aggressive with participants in the company. A Sunday screening at the Cannes Film Festival received a two-minute-long ovation ... and marked the first time Shia saw the doc, per Variety.