Leonardo DiCaprio's Ex Bar Refaeli Flaunts Bikini Body

Bar Refaeli looks like she could still model for Sports Illustrated ... because she's rocking the hell out of some sexy swimwear.

Leonardo DiCaprio's ex-girlfriend just posted a bunch of thirst traps on social media ... and she's wearing an itsy-bitsy teeny-weeny bikini.

Bar snapped some sultry mirror selfies in her red 2-piece and then took the show into the water, hopping into a pool to continue her impromptu photo shoot ... getting all the angles and showing off her assets.

The supermodel is 40, with three kids, and has been modeling since she was 8 months old ... she's not far off from her SI Swimsuit magazine days, and the proof is in the photos.