The 33-year-old Keeping Up With the Kardashians star got dolled up for the occasion, wearing a skintight, cleavage-enhancing leather black dress, while 17-year-old Kylie kept things a little simpler in a midriff-baring black ensemble.
Of course, Kanye wasn't the only attraction at the second annual "Made in America" festival. John Mayer, Kings Of Leon, Pharrell Williams, Iggy Azalea and Rita Ora were also among the performers at the Jay Z-founded event.
And speaking of Hov, he and wife Beyoncé were spotted getting cozy in Roc Nation's VIP section as they watched DJ Steve Aoki perform. This came just one week after the couple squashed divorce rumors with a lovey-dovey show of affection at the 2014 MTV VMAs, where Bey was awarded the Vanguard Music Video Award and fêted by her hubby and daughter, Blue Ivy.
Crazy in love, indeed.
Be sure to catch Kourtney & Khloé Take the Hamptons, premiering this fall on E!