Katy received the prizes for best video, for "Dark Horse," and best look. She did not attend the ceremony.
Boy-band One Direction collected three awards, while Ariana Grande and 5 Seconds of Summer each picked up two.
Here are the winners:
Best PopOne Direction
Best FemaleAriana Grande
Best LiveOne Direction
Best New5 Seconds of Summer
Best VideoKaty Perry -- "Dark Horse ft. Juicy J"
Best AlternativeThirty Seconds to Mars
Best Hip HopNicki Minaj
Best ElectronicCalvin Harris
Biggest FansOne Direction
Best LookKaty Perry
Best Push5 Seconds of Summer
Best Song with a MessageBeyoncé, "Pretty Hurts"