A gold colored metal and green epoxied shamrock shaped device, 1 (2.54 cm) in height.

The shamrock is an insignia used by the Army ROTC cadets at Notre Dame University. The shamrock is a leaf of a trifoliate plant which is accepted as the National Emblem of Ireland from its legendary use by St. Patrick to typify the Trinity. The shamrock is also noted on the original flag of the 63rd Regiment N.Y.S.V., Irish brigade, a Civil War Unit.

The shoulder loop Insignia was originally authorized on 12 July 1968, currently amended to update the manufacturing drawings on 27 January 2016. 

On a shield shaped embroidered item edged with a 1/8 inch (.32 cm) dark blue border, blazoned as follows: Celeste, in base two bars wavy Argent, superimposed upon the first bar wavy a long cross pattée of three points Or, surmounted on its lower limb an open book of the last, pages Argent with the inscription in Latin “VITA, DUL-, CEDO, SPES” Azure (dark blue), in dexter chief a mullet of six-points of the first. Attached above the shield, a Light Blue scroll edged with a 1/8 inch (.32 cm) dark blue border, inscribed
“FIGHTIN’ IRISH” in yellow. The overall dimensions are 3 1/2 inch (8.89
cm) in height by 2 3/8 inch (6.03 cm) in width.

Blue and gold alludes to the Virgin Mary which the university is named and dedicated. The wavy bars suggest the two lakes located on the campus of Notre Dame. The open book’s Latin inscription, “VITA, DULCEDO, SPES” translates to “Our life, Our sweetness, Our Hope,” the combination of these phrases indicates the commitment of all students to Notre Dame’s activities, intellectual, spiritual and athletic. The six-pointed star signifies the epithet
“Our Lady, Star of the Sea”, also denoting the ancient symbol of the Virgin Mary.

The shoulder sleeve was originally authorized on 26 May 1978. It was cancelled on 18 March 2020 due to a new design and description.