Credit: Splash News Online

Happy birthday to one of the most enviable bods in Hollywood: Audrina Patridge!

To celebrate her 27th birthday, Us Weekly is looking back on the Hills alum's hottest bikini moments.

Even before she appeared on Dancing with the Stars in late 2010, the California beauty -- who is a natural blonde -- has always has an enviable figure. But she attributes the hit ABC competition as the experience that really kicked her body into shape.

"I would say I'm in the best shape of my life," she told Us of the results she saw from the demanding rehearsals. "Dancing is so different than going to the gym. I'm going to be so sad when it's over!"

"I feel more toned and more defined for sure," she continued. "I have maintained my weight, but I'm really, really defining my muscles and toning up."

Click here to view the star's sexy, skin-baring bikini style.