Katie Cassidy & Colton Haynes: 'Arrow' Cast Takes Over iHeartRadio Festival!

Katie Cassidy arrives in style on the red carpet at the 2013 iHeartRadio Music Festival held at the MGM Grand Garden Arena on Saturday night (September 21) in Las Vegas, Nev.

The 26-year-old actress was joined at the event by her Arrow co-stars Colton Haynes, Willa Holland, and Emily Bett Rickards!

PHOTOS: Check out the latest pics of Katie Cassidy

The night before, Stephen Amell joined Twilight stars Ashley Greene and Jackson Rathbone on the red carpet for Day 1 of the music festival.

Be sure to check out Colton and Stephen both shirtless on the latest set of Arrow cast posters!

FYI: Katie is wearing Alice and Olivia.

25+ pictures inside of the Arrow cast at the iHeartRadio Festival…