Sir Paul McCartney, Metallica and Florence + the Machine will headline Lollapalooza.

The Beatles star will perform on the opening night of the festival in Chicago's Grant Park, with the 'Enter Sandman' musicians headlining the Saturday evening before Florence Welch's band close the festival the following evening.

The announcement marks the 'Let It Be' hitmaker's first performance at the three-day annual festival, while Metallica, who first headlined the event in 1996, have played at Lollapalooza on several occasions.

Other acts confirmed for the event - which runs from July 31 until August 2 - include four-time Grammy Award winner Sam Smith, indie band alt-J, 'Boom Clap' hitmaker Charli XCX, 'Yonkers' rapper Tyler the Creator, and rockers Alabama Shakes.

Additionally, the line-up of 130 confirmed acts features The Weeknd, Marina & the Diamonds, FKA twigs, Kid Cudi, Of Monsters and Men, Alesso and A$AP Rocky.

Spread across eight stages, the popular festival - which last year featured headline performances from Outkast, Kings of Leon and Eminem - is expected to welcome 100,000 music fans to each of the three days.