Katy Perry used to pretend she was Zooey Deschanel to get into clubs.

Katy Perry and Zooey Deschanel

Katy Perry and Zooey Deschanel

The two stars have often been told they look like one another and the 'Not the End of the World' singer admitted she took advantage of having a more famous doppelganger when she first moved to Los Angeles.

Speaking to Zooey on Instagram Live, Katy said: "When I moved to L.A. maybe 18 years ago... I was pretty much a nobody, and you were like just getting so huge at that time, it was like Zooey Deschanel ran the world.

"In that moment, I was so complimented to look like you.

"But I have to admit something to you. When I first got to L.A., I went to the club. A lot. And I wanted to get into the club, but I had no money, I had no clout, I had nothing, and sometimes I would pose as you to get into the club."

Much to Katy's shock and embarrassment, the 'New Girl' star was already aware because she's a "goody two-shoes" and yet people were always convinced she'd been out partying.

Zooey replied: "Well, I know this. People were like 'I saw you!' But I'm such a goody two-shoes, and people kept going like, 'I saw you out! I made eye contact with you!'

"Then everybody kept telling me about you, 'This girl Katy, she looks just like you,' and I'm like, 'Who is this Katy?'

"And then when I first met you, I was so relieved because you're so pretty, and I was like, 'Oh, thank God. She's so pretty."

The 36-year-old singer confessed she was always "tuned up to 11" and acted wild when she was in clubs.

She added: "So I'm sorry if I misrepresented you."

But Zooey - who is kidnapped by aliens who think she is the pop star in Katy's new music video for 'Not the End of the World - reassured the 'Firework' hitmaker she found the confusion a compliment.