Festivalen ble arrangert fra 23 Jun til 05 Jul 2015 (12 dag(er)).
Summerfest finner sted i Milwaukee, United States. Her er den fullstendige adressen til festivalen: Henry Maier Festival Park; Milwaukee, Wisconsin, United States
Ed Sheeran, Chase Atlantic, Zac Brown Band, Thomas Rhett, Kendrick Lamar, The Rolling Stones, Mother Mother, Kings of Leon, Keith Urban, A Day to Remember, Bastille, Kaleo, Carrie Underwood, Lindsey Stirling, Brandi Carlile, The Doobie Brothers, Coheed and Cambria, Third Eye Blind, The Kooks, Flogging Molly.
De mest populære sjangrene og undersjangrene i den siste utgaven var:
rock
pop
country
alternative
alternative rock
indie
indie rock
indie pop
classic rock
hard rock
pop rock
southern rock
blues rock
acoustic
emo
americana
rnb
country pop
dance