Kim was there to support her fiance, Kanye, who last week reportedly spent $6 million popping the question at a baseball stadium, while Cheryl was there to see Yeezus at work.
Taking to Twitter after the concert, Cheryl revealed she's a big admirer of the rapper.
"Kanye West is a genius #fact," she wrote.
CC and KK struck up a friendship online earlier this year, when the former 'X Factor' judge defended the 'Keeping Up With The Kardashians' star after she received nasty comments about her pregnancy weight.
Cheryl wrote: "Just wanted to send you a tweet to say I think you are an incredibly beautiful woman inside and out.
"I can only imagine how tough it is to be heavily pregnant and feeling extremely vulnerable on top of some of the daily criticism you take! I admire your tenacity and send you my best wishes with the rest of your pregnancy."
Kim replied saying: "Your message really touched me! Thank you so much for the support & positivity! Its so important for women to feel confident & at peace during this amazing time! Your sweet tweet really made me smile!"
Kim's sister Khloe also met Cheryl at the concert on Sunday and tweeted that the Geordie star was her "soul sister":
Could we soon see a Cheryl cameo on the Kardashians' reality show?