A Gold color metal and enamel device 1 1/8 inches (2.86 cm) in height overall consisting of a Spartan shaped shield blazoned: Or, a chevron Sable to chief arrayed on a sun in glory, in dexter a cornucopia to sinister a portion of a trestle bridge and in chief an open book all of the first, to base a wavy of four Celeste, overall in base a depiction of the Spartan King Leonidas spear raised in his dexter hand, shield held to sinister. Attached above the shield a Black ribbon scroll inscribed "LATHROP H. S." in Gold letters. Attached below the shield a Black ribbon scroll inscribed "DUCIMUS" in Gold letters.
The school colors are black and gold. The Spartan is the school's mascot and describes the courageous spirit of the student body and school staff. The Spartan is surmounting waves which represent the San Joaquin River, the life blood of the community. Superimposed on a background of the shining sun to represent the sunshine state are three symbols, the cornucopia describes the agricultural bounty of the area. The trestle bridge indicates the importance of the rail system to the growth of the area and the bridge itself reflects a sense of unification and community. The open book is the symbol for learning, and "DUCIMUS" is the school's motto which translates to "We Lead".
The shoulder loop insignia was authorized 8 January 2010.