A Gold color metal and enamel device 1 1/8 inches (2.86 cm) in height consisting of a shield blazoned: Or, on a saltire Azure between in fess a cross pattée and a five-bastioned fort Gules and in base a giant cactus Vert, two arrows in a quiver Proper crossed with a bolo Argent hilted Sable. Attached below the shield is a Blue scroll inscribed "NOLI ME TANGERE" in Gold letters.
Service in the Civil War is shown by the blue cross from the Confederate flag and the red cross pattée, the badge of the 18th Division, V Corps, in which the regiment served during the greater part of that war. Service in the Mexican War is shown by the cactus; in the War with Spain by the five-bastioned fort, the badge of the V Corps in Cuba. The Indian campaigns of the regiment are shown by the arrows and quiver, and the bolo is for service in the Philippine Insurrection.
The first design for the distinctive unit insignia of the 2d Infantry Regiment was approved on 20 February 1920. That design was cancelled and the present design authorized for the regiment on 19 June 1936.