Emily Ratajkowski Poses Completely Naked on Lounge Chair

Emily Ratajkowski's not letting even the tiniest bikini mess up her tan ... stripping down to her birthday suit to soak up the sun in a photo she just posted to Instagram.

The model shared the pic in a photo dump from this month ... lying back, phone in hand, with a leg kicked up to obscure her downstairs area.

She uses her arms to cover up her nipples ... and throws a small smile to the camera while she looks totally relaxed on her vacation.

EmRata also shared other hot pics from her trip ... donning barely-there swimwear, tiny crop-tops and enjoying decadent meals with her friends.

She captioned the snap "luglio" ... the Italian word for July -- so, it's possible she went on a Roman holiday, though we don't know that for a fact.

Tons of celebs are using the summer months to flaunt every inch of their bangin' bods ... just take Nicola Peltz, who shared a photo of herself stretched out nude in a bathtub.