The Firework singer is the latest artist to sell off the rights to her past hits - but what does that mean?
From Tom Cruise and Ellen DeGeneres, one sign you are really famous is when rumours star circulating that you do not allow your employees to look you in the eye.
Perry's hit song 'Dark Horse' references the serial killer.
BBC radio presenter Scott Mills has remembered some of of his favourite celebrity encounters from his time at Radio 1, as he prepares to move to Radio 2 in the autumn.
The 'Pirates of Caribbean' star is certainly reinventing the 'dad bod' in his own special way.
Ellie Goulding's famous friends have been helping her out as she prepares to become a mother for the first time.
Katy Perry appeared on "Jimmy Kimmel Live!," Monday, where she talked about the joy and surprises of motherhood.
The pop star performed 'Firework' at the event.
The singer called him a "brilliant father" in her post.
Before she achieved megastardom, the singer used her resemblance to the actor to her advantage.
Miranda Kerr has spoken of the relationship she enjoys with father of her son and ex-husband Orlando Bloom and his fiancée Katy Perry
The actor urged his fans to consider fostering.
The actor said his and Katy Perry's baby is a 'mini-me' but has the singer's eyes.
The singer welcomed her daughter Daisy in August.
Taylor Swift has gifted Daisy Dove Bloom with a hand-embroidered blanket.
The pair were married for 14 months before Brand ended things.
The singer appears to have an ode to her daughter on her latest album, 'Smile'.
Perry met Sia in 2014, and they bonded over their struggles with mental health issues.
The singer publicly voiced support for DeGeneres and her show but received criticism from followers.
The pop star's partner appeared shirtless as he gatecrashed her livestream.
The 'Roar' singer has lifted the lid on why she and Swift made up in the public eye last year.
The star revealed a tattoo tribute to his beloved pet, who he said was now 'on the other side'.
The actor is offering a reward for Mighty's return.
Katy Perry's mental health suffered after she was disappointed by the reception to her album 'Witness'.
The singer is expecting a baby girl.