Jennifer Coolidge told cops she had an unwelcome visitor takin' a stroll on her property ... and we're told there's now an investigation for the trespass.
Law enforcement sources tell TMZ ... JC noticed the unknown man last month while reviewing security tapes -- which apparently show him walking up to her L.A. area home.
We're told the man tried to open Jennifer's security gate -- to no avail -- which is when he jumped over the gate and continued to walk around her property before eventually taking off.
Police were called and a trespassing report was taken. The man in question may have just been transient in the area. No arrests have been made, at least not yet.
We've reached out to Jennifer's people for comment ... so far, no word back.
Doesn't sound like the man got close enough to actually take anything ... but as you know, she could've had her recently acquired Golden Globe on her mantle, after her hilarious F-bomb-filled acceptance speech back in January.
Trespassers beware, you don't wanna mess with the Coolidge -- have you seen her in "The White Lotus?"