The event, now in its fourth year, will be held on the weekend of June 18th to 25th.
Festival officials say a third headlining act will be revealed at a later date. Rumors on the internet point to that name being Paul McCartney - SPIN, Radio104.5 - but that has not been confirmed.
The 2015 lineup also features Morrissey, Snoop Dogg, Foster the People, Bastille, Modest Mouse, Zedd, Hozier, Empire of the Sun, Kid Cudi and nearly 100 additional acts performing across seven stages.
Tickets will go on sale at a future yet to be announced date.
In 2012, Firefly attracted 30,000 attendees in its inaugural year and jumped to more than 80,000 in 2014.
In late 2014, festival organizers Red Frog Events partnered with Goldenvoice, the creators of Coachella, to produce and promote Firefly.