World War I (also known as WW1 or The Great War) was a global conflict featured in Call of Duty: Black Ops II and Call of Duty: Black Ops III on the Zombies map Origins. The player will not be able to fight in the war, because Zombies have overrun the map. There are planes flying around the map and shots being fired into the skies, which suggests that fighting is happening during the course of the map. Origins takes place in the trenches in Northern France.
- Jean-Guy Robiechauld and Stan Jackowicz from Call of Duty 3 were veterans of this war.
- World War I is mentioned by Colonel Davis at the start of the mission Death Factory in Call of Duty: WWII.