Call of Duty 2: Big Red One is a World War II video game for home consoles, released on November 1, 2005 in Canada and the United States. While developed by Treyarch, personnel from Gray Matter Interactive (who created the award-winning Call of Duty: United Offensive expansion pack for the PC) also worked with them on the game. Pi Studios contributed work as well.

Big Red One differs from other games in the Call of Duty franchise in that it focuses on a single Allied formation in the War: the U.S. Army’s 1st Infantry Division, which also went by the nickname Big Red One due to their unique patch. The game covers the division’s part in the invasion and liberation of North Africa, the invasion into Sicily, the landing on Omaha Beach in Europe and moving east, eventually crossing the Siegfried Line into Germany. At the end of each chapter and the beginning of the first, period footage with voiceover (courtesy of Mark Hamill) is seen from the "Military Channel", imitating a WW2 documentary.

The game features two actors from the miniseries Band of Brothers: Michael Cudlitz (Sgt. Denver ’Bull’ Randleman) and Frank John Hughes (Sgt. Bill Guarnere). Cudlitz voices Sgt. Glenn "Hawk" Hawkins and Hughes voices Pvt. Alvin "Brooklyn" Bloomfield.

The box cover features actor Stephen Saux. The story and characters were written by Aaron Ginsburg and Wade McIntyre.

In CoD:BRO, you play as the same soldier throughout the entire campaign. Under the leadership of Sgt. Hawkins, you go where the Big Red One went in Operations Torch (Africa), Husky (Sicily), and Overlord (Europe), on land, sea, and air.

The game starts out with a brief tutorial level that takes place somewhere in France. After that the next level is a flashback that takes place shortly after the amphibious invasion of Algeria at the Battle of Oran (Later in the game, in the level "An Easy Detail" there is a reference to the France tutorial level, signifying the end of the flashback). The game then moves on to Kasserine Pass, and Kasserine, and the final battle in the North Africa campaign is where the player fights as the main character’s brother in a B-24 Liberator over the Mediterranean.

Then Operation Husky begins with the Battle of Gela, where you have to rescue paratroopers of the 82nd Airborne. At Piano Lupo, you defend the paratroopers against the Panzer Division Hermann Goering, and at Troina, you consolidate the city and capture Sicily.

After your unit is moved to England, you participate in the D-Day invasion, destroying bunkers and warehouses, and finally taking control of a Flak 88 gun to win the level. The game moves on to Mons and Eilendorf, where you move closer and closer to Germany.

The last two levels are at Buchholz and the Siegfried Line, where you lead your soldiers over the final crossing into Germany in the snowy winter of 1945. The game ends after the V2 rockets at the Siegfried Line are destroyed, and you have won.

BRO tends to focus much more heavily on the character aspect of your squadmates. You learn their names and watch them as they age and gain rank over the course of the war (and are killed in combat).