ShieldArgent, two chevronels Azure, upper charged with six fleurs-de-lis, lower charged with ten mullets Or; in base a lion rampant Gules, langued and armed of the second, all within a diminished bordure of the fourth.
CrestThat for the regiments and battalions of the Pennsylvania Army National Guard: From a wreath Argent and Azure, a lion rampant guardant Proper holding in dexter paw a naked scimitar Argent hilted Or and in sinister an escutcheon Argent on a fess Sable three plates.
ShieldThe shield is white, the old color of Infantry; the chevronels are in blue, indicating that the organization's service during the Civil War and World War I was as Infantry. The ten mullets or stars represent the ten battle honors of the Civil War period and the six fleurs-de-lis, the World War I service. The red lion denotes service in the War of 1812. The red border signifies that the organization is now an Engineer unit.
CrestThe crest is that of the Pennsylvania Army National Guard.
The coat of arms was originally approved for the 103d Engineer Regiment, Pennsylvania National Guard on 12 December 1931. It was redesignated for the 103d Engineer Battalion, Pennsylvania Army National Guard on 3 September 1942. It was amended to correct the blazon on 1 June 2016.