MW4

MW4 may refer to:


 * MechWarrior 4: Vengeance, a 2000 video game
 * MechWarrior 4: Mercenaries, a 2002 video game
 * Call of Duty 4: Modern Warfare, a 2007 video game
 * An abbreviation of master warrant officer in the United States Armed Forces
 * a model of Microwriter, a hand-held portable word-processor