Kylie Jenner
Credit: kyliejenner/Instagram

Need some inspiration for your swimsuit selections? Kylie Jenner, Ellie Goulding and other stars who showed off their killer curves in bikinis and more on Instagram this week might be able to give you just that.

As the 18-year-old Keeping Up with the Kardashians star got ready for her Kendall & Kylie swim shoot for Topshop Wednesday, she posted a selfie that showed her posing in a yellow-and-black bikini from her collection. The social media darling was just one of many stars who hit the social media site with photos of themselves in their best beach and poolside attire, like mom-to-be Bar Refaeli who pretended to catch a rainbow in a throwback bikini shot.

Whether you need bikini inspo, fitspo, or ideas for new bikini snaps, take a peek at this week's best swimsuit Instagram photos (James Franco even makes a cameo)!:

Bar Rafaeli:

Shay Mitchell:

Vanessa Hudgens:

James Franco:

Ellie Goulding:

Serena Williams:

Bella Hadid:

Hilary Duff:

Kylie Jenner: