The 3rd Division was activated in November 1917 during World War I at Camp Greene, North Carolina. Eight months later, it saw combat for the first time in France. At midnight on 14 July 1918, the division earned lasting distinction. Engaged in the Aisne-Marne Offensive as a member of the American Expeditionary Forces (AEF) to Europe, the division was protecting Paris with a position on the banks of the Marne River. The 7th Machine Gun Battalion of the 3rd Division rushed to Château-Thierry amid retreating French troops and held the Germans back at the Marne River. While surrounding units retreated, the 3rd Infantry Division, including the 4th, 30th and 38th Infantry Regiments, remained steadfast throughout the Second Battle of the Marne, thus earning its nickname as the "Rock of the Marne". The rest of the division was absorbed under French command until brought back together under the command of General Joseph T. Dickman and by 15 July 1918 they took the brunt of what was to be the last German offensive of the war. General of the Armies John "Black Jack" Pershing, who commanded the entire American Expeditionary Force, called this stand "one of the most brilliant pages in the annals of military history". During the war two members of the division were awarded the Medal of Honor.

Casualties during the war were 3,177 killed in action with 12,940 wounded.