Let's face it -- pop stars are H-O-T. Whether it's their confidence or sex appeal, these pop stars know how to turn up the heat.. but who is the hottest of them all? That's why we are asking you to help us crown PopCrush's Hottest Male and Female Star of 2013!

So let's get started. We've got eight studs and eight lovely babes that we've separated into groups (male and female) of two for one-on-one battles. The hot star who wins Round 1 will then go on to face another competitor in Round 2, and so on until we have narrowed down our list of 16 to the Hottest Male Star and the Hottest Female Star. It's important to know that YOU decide who is deserving of these titles.

For Hottest Male Star, we've got celebs with the best looking washboards on the block. Justin Bieber is up against Harry Styles of One Direction in Round 1, while Aussie hottie Cody Simpson is taking on cutie Austin Mahone. James Maslow of Big Time Rush will compete against Adam Levine of Maroon 5, while Chris Brown will go head-to-head with Jason Derulo.

Meanwhile, we've got gals with killer curves in the Hottest Female Star category. Former Disney stars Selena Gomez and Miley Cyrus will battle it out, while Demi Lovato will take on country-pop cutie Taylor Swift. Rihanna will duke it out with another diva who oozes sexiness -- Beyonce, and Lady Gaga will be challenging (who else!), Katy Perry.

So, who will come out on top in the Hottest Star of 2013? Voting for Round 1 will run until Aug. 30, at 2PM ET -- and then four competitors in each category will continue on to Round 2 and so on. Good luck!