A gold color metal and enamel device 1 3/16 inches (3.02 cm) in height consisting of a white four-sided fort with two bastions, one up and one down, bearing two blue horizontal bands surmounted by a scarlet six-pointed star; issuing from the fort six arrows with gold shafts and scarlet heads, three to the right and three to the left, all surmounting a green disc within a gold encircling scroll the upper part inscribed WE SERVE and the lower WE PROTECT in red letters.
The fort represents Fort Dearborn, the United States military garrison which protected the settlements that later became Chicago, headquarters of the 33d Military Police Battalion. The blue bands and scarlet six-pointed star are from the flag of Chicago. The six arrows radiating from the fort stand for military protection; they are divided into two groups of three each in reference to the Battalions numerical designation. The arrows also allude to the six tribes of the Illinois Indians, first inhabitants of the area. The green background stands for the Great Plains of Illinois, long called the Prairie State. The colors green and yellow are used for the Military Police Corps.
The distinctive unit insignia was approved on 17 September 1969.