Like every other North American music festival, Lollapalooza is celebrating a milestone in 2011 — Perry Farrell’s annual music extravaganza is no longer a teenager. The festival turns 20 during the weekend of August 5-7 and it will celebrate in Chicago’s Grant Park with a lineup topped by Eminem, Foo Fighters, Coldplay, Muse, My Morning Jacket, and Deadmau5.

Other heavyweights include A Perfect Circle, Bright Eyes, The Cars, Big Audio Dynamite, Ween, Arctic Monkeys, Damian “Jr. Gong” Marley and Nas, Explosions in the Sky, Death From Above 1979, Deftones, Cee-Lo Green, Beirut, Flogging Molly, OK Go, The Kills, and Cold War Kids.

A number of indie favorites are confirmed, including The Mountain Goats, Atmosphere, Titus Andronicus, Ratatat, Best Coast, Crystal Castles, White Lies, Lykke Li, Local Natives, Black Lips, Delta Spirit, Sleigh Bells, The Pains of Being Pure at Heart, Wye Oak, The Drums, Smith Westerns, The Naked and Famous, Phantogram, Dale Earnhardt Jr. Jr., The Joy Formidable, Young the Giant, and Cults.

If that weren’t enough, Fall Out Boy’s Patrick Stump, Ryan Bingham & The Dead Horses, Grace Potter & the Nocturnals, Cage the Elephant, Rival Schools, The Chain Gang of 1974, Friendly Fires, Portugal. The Man, Manchester Orchestra, Two Door Cinema Club, Noah & The Whale, Lissie, Foster the People, Mayer Hawthorne & the County, Fences, City and Colour, and Gold Motel are also confirmed.

This year’s edition will also feature an expansion of Perry’s Place, the festival’s electronic-oriented stage. Designed to accommodate a crowd of 15,000, the area will host the likes of Girl Talk, Kid Cudi, Pretty Lights, Skrillex, The Glitch Mob, Jay Electronica, Modeselektor, Daedulus, Feed Me, Busy P, and Joachim Garraud.

Find a complete list of confirmed acts at our Festival Outlook.

Three day and VIP passes are priced at $215.00 and $850.00, respectively, and are now available via the festival’s website.