Taylor Swift continues to bring the big names to her 1989 world tour - the latest VIPs to strut their stuff on stage with the popstar include Julia Roberts, Joan Baez and Little Mix.

The 25-year-old Grammy-winning singer certainly knows how to drive a crowd wild with her surprise celebrity guests and the latest additions to her line-up are no different. 

Oscar-winning actress Julia Roberts delighted the crowd by joining Swift on stage during a performance of hit song Style last night in California, accompanied by award-winning folk singer Joan Baez.

And if that wasn't enough for fans, X Factor winners Little Mix performed their smash Black Magic with Swift.

Writing on their joint Instagram page after the show, the girls said: "OMG cannot quite believe what's just happened, one of the best experiences in our Little Mix life ever!

"Cannot thank Taylor enough for having us tonight, 60,000 incredible screaming swifties with a sprinkle of Black Magic, thank you for being so welcoming to us!

"We love you Taylor can't wait to catch up very soon! xx Little Mix xx"

During the tour, the singer has welcomed onstage a slew of celebrity friends, including Cara Delevingne, Kendall Jenner, Gigi Hadid, Serena Williams, Fifth Harmony and Nick Jonas.