The former 'X Factor' star partied with friends including Nicola Roberts, Kimberley Walsh and Black Eyed Peas singer will.i.am at the exclusive party, which she is using as an opportunity to "jumpstart" her career following her shock sacking from the US version of the singing competition.
A family friend told The Sun newspaper: "Her moping about 'The X Factor' is over. She's determined to jumpstart her career. She still has America in her sights."
Cheryl wore a 60s style Stella McCartney white dress for the occasion, teamed with high heeled shoes.
However, her ex-husband Ashley did not make an appearance as some had expected.
Cheryl has only been seen in public twice since she was replaced by Nicole Scherzinger on 'The X Factor', but before her first return - at the US embassy in London earlier this week - she was keen to tell her fans she was doing fine.
She wrote on her website: "I have had the time that I have not had in so long to just chill with my loved ones and do the normal things that I like to do. See my friends and family and be with my doggys. It feels long overdue and sooooo good, even my feet are happy to not have to wear a pair of high heels hehe.
"It also breaks my heart a little when i hear that some of you worry about me and need to know that I am ok, so I want to PROMISE you that I am absolutely fine and more than OK! (sic)"