Katy Perry

Ever wanted to hear Ellen DeGeneres cover Katy Perry's 'Birthday'? Well, you're (sort of) in luck, as we have the closest thing that we're going to get to a genuine remake.

John Mayer was asked by TMZ on the idea that his ex Katy Perry will be writing songs about him. "You're supposed to write songs. You're just not supposed to tell everyone you're doing it."

Katy Perry has accomplished a lot in her career -- and now she can add "first-ever global Cosmo cover star" to her list.

Like Katy Perry, you're gonna hear this elephant roar.

American Authors recently shared their awesome prom playlist with us -- and now, they've put together the perfect graduation mix, featuring everything from Katy Perry's 'Firework' to Queen's 'We Are the Champions' to the traditional graduation march, 'Pomp and Circumstance.'

Last night (May 7) Katy Perry launched the ‘Prismatic World Tour’ in Belfast, Ireland, in an incredible display of colorful costumes, complicated choreography, and seriously impressive stage setups.

Katy Perry has finally and officially confirmed what the world knows and is painfully obvious -- that she and BF John Mayer have split.

Chalk it up to another reason I love Katy Perry...she's hysterical. Her new video for her song "Birthday" comes out tomorrow (4.24.14), and she released a "trailer" for it, playing lots of different characters who are allegedly the "world's worst birthday party entertainers". ...

Pop and country are colliding not just on Taylor Swift albums, but at the taping of the 'CMT Crossroads' Katy Perry x Kacey Musgraves special. Get a sneak peek at some pics and some video from the performance.

Move over, Robert Pattinson, Riff Raff and John Mayer, the rumored hookups and official ex of Katy Perry. The singer and supreme catch may be dating DJ Diplo.

Fans, next time you see Katy Perry, you might want to think twice about taking out your cellphone and trying to grab a selfie with the pop superstar.

Warning: You will want to nom all of the incredible-looking confections in Katy Perry's lyric video for her song 'Birthday.' Just letting you know in advance.