Jeff Goldblum's trip to Hawaii isn't all sunshine and rainbows ... because he claims he got his belongings straight-up jacked from a hotel locker while he was taking a dip in the ocean.
Law enforcement sources tell TMZ ... Jeff filed a police report over the weekend after his personal items were stolen out of a locker at the Outrigger resort in Waikiki, and cops are investigating.
We're told the "Jurassic Park" actor crammed a bunch of his stuff into a locker before diving into the Pacific, and when he came back to shore his stuff was nowhere to be found ... so he called the cops.
As you can see ... Jeff was still dripping wet when he was talking to police on the beach. Talk about a buzz kill after frolicking around in the salt water.
Jeff and his wife, Emilie Livingston, are hanging in Oahu while he plays some gigs with his jazz band ... but they won't be going back to the mainland empty handed despite the theft. At least Jeff got a tan!