Heather Graham is in full summer mode on her Italian vacation … stripping down to a tiny bikini while enjoying the sun and surf in Sardinia.

The “Boogie Nights” actress walked around the beach late last week … wearing a skimpy black, thong-style bikini and a floppy white sun hat to keep the blinding sun off her face.

It looks like she’s trying to keep a low profile in a pair of dark sunglasses … but, her bod certainly drew eyes — so, it probably didn’t work like a charm.

While many of the jurors were foreign filmmakers … Alec Baldwin also served on the panel — talk about heavy hitters in Sardinia!

Heather’s getting a well-deserved break before she gets busy once again … ’cause she’s got multiple projects — including a “Carrie” show based on the Stephen King novel and movie of the same name — coming soon.