Call of Duty 4: Modern Warfare is a first-person shooter developed by Infinity Ward and published by Activision for Xbox 360 , Playstation 3 and PC. It is the fourth installment in the Call of Duty video game series (excluding expansions), the first not to be set during World War II. It was announced on April 25, 2007. It was released on November 6, 2007 in North America, on November 7, 2007 in Australia, and on November 9, 2007 in Europe. The game also became available on Steam on November 6, 2007 for pre-purchase and is available to play as of November 12, 2007.

Call of Duty 4: Modern Warfare introduces a variety of game play styles into the single player campaign completely new to the Call of Duty series. The game moves away from the standard three country-specific campaign style, and allows the plot to play through more like a film style plot with interlaced story lines from the perspective of the player as Paul Jackson, a member of the United States Marine Corps 1st Force Recon and "Soap" MacTavish, a member of the British 22nd SAS Regiment. There is also a variety of cameo-style missions where you play as various other soldiers such as an AC-130 Spectre Gunship gunner, or as one part of a two-man sniper team behind enemy lines in a flashback-style mission.

Call of Duty 4: Modern Warfare focuses on the variation of modern warfare as an infantry soldier by allowing the player to control soldiers in a vast number of different scenarios, straying away from the constant straightforward action of previous Call of Duty titles and allowing for both heavy intensity fire fights and slower paced drama styled intensity. The series' move to modern warfare has also introduced a variety of new modern weapons and technology to be introduced to the Call of Duty franchise. Such showcased weapons and attachments include M203 grenade launchers, and the AN/PEQ-2 Target Pointer for use in conjunction with night vision goggles, MP5SD submachine guns, the M4A1 Grenadier, and the FGM-148 Javelin portable anti-tank guided missile among many others.