Instagram: : @theashleygraham
Followers: 3 million

Graham went down in history as the first plus model to cover the famous Sports Illustrated Swimsuit Issue.

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Instagram: : @yoventura
Followers: 4.7 million

Justin Bieber's former gal pal, who seems to spend all her time in bikinis and butt-hugging spandex, has enough social media followers to fill a small country.

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Instagram: : @sarasampaio
Followers: 4.6 million

We're pretty sure this Portuguese model (she's a Victoria's Secret Angel) was born wearing a bikini.

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Instagram: : @missdollycastro
Followers: 5 million

Fitness model Castro has her own line of athletic apparel and accessories, Bars & Branches -- not to mention Instagram's best abs.

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Instagram: : @karrueche
Followers: 6.1 million

Ever since the African American/Vietnamese stunner dropped Chris Brown like a hot potato, she's had a lot more time to steam up the world's Instagram feeds.

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