AC-4 or AC4 may refer to:
Music AC4 (band), a Swedish hardcore punk band, or their eponymous album
Vehicles Aircraft Light Wing AC4, an aircraft Aviastroitel AC-4 Russia, glider Comte AC-4, a two-seat Swiss monoplane
Ships , a US Navy collier ship
Trains Southern Pacific class AC-4, a class of steam locomotive
Tanks AC4 tank, a World War Two Australian cruiser tank
Technology AC-4, an IEC Utilization Category Dolby AC-4, Dolby Digital audio codec
Videogames Ace Combat 04: Shattered Skies, a 2001 video game Armored Core 4, a 2006 video game Assassin's Creed IV: Black Flag, a 2013 video game
See also
AC (disambiguation)