The Army Medal is a Polish military decoration, established by the Polish government-in-exile on July 3, 1945. The medal became a commemorative award for soldiers of the Polish Army who fought with the Allied forces in the West during World War II.

The Army Medal 1939-45 was awarded:
- for 6 months of service in combat units of the Polish Army;
- for 12 months of service in service units.
The term of service was calculated from September 1, 1939, until the end of the war. A single service member could be awarded a maximum of four times. For a second award, the length of service was doubled. A medal was not issued for a second award; instead, a pin to the award ribbon and a document confirming the second award were issued.

In addition, the government may decide to award the medal to a service member who has not fulfilled the service requirement if they have committed actions exceeding their service term.
The award was made of bronze and was a round medallion with a rim, 36 mm in diameter. The obverse of the award depicts a Polish royal eagle holding a sword in its claws, its tip pointing to the right. The reverse bears the three-line inscription "POLSKA SWEMU OBRONCY" (Poland to its defender), with an oak leaf above and below the inscription.
The award is attached to the award ribbon via an eyelet and ring. The award ribbon is a dark red silk moiré ribbon, 36 mm wide, with four white stripes 2 mm wide: two at the edges and two 4.5 mm from the center.
The repeat award bar, also bronze, is 5 mm wide and decorated with oak branches radiating from the center.
The Army Medal 1939-1945 is worn on the left chest.