Armee) was a World War II field army.The 1st Army was activated on 26 August 1939, in Wehrkreis XII with General Erwin von Witzleben in command.

Its primary mission was to take defensive positions and guard the western defences (West Wall) of Germany against Allied forces along the Maginot Line during the attack on Poland,[1] making it the principal German combatant during the short-lived French Saar Offensive.

the 1st Army continued its defensive assignment on the French border until June 1940, when the Battle of France had turned decisively to Germany's favor.

In November 1944, both defensive lines were broken and the First Army retreated to the German border and defended the Saarland of Germany, an important industrial region.

With the failure of Nordwind in late January, the 1st Army was first pushed back to the Siegfried Line and then forced to retreat across the Rhine River.