The flag of the fictional Empire of Vietnam, as depicted, consists of a yellow field with three horizontal red stripes. Its design is a direct variation of the historical flag used by the State of Vietnam and the Republic of Vietnam (South Vietnam), known as the Heritage and Freedom Flag. The defining feature of this alternate design is the break in the center of the middle red stripe, creating two shorter bars separated by a yellow gap. While the traditional yellow background represents the land and people of Vietnam, and the red stripes symbolize the blood and struggle for nationhood, the broken central stripe distinguishes it from its real-world counterpart, perhaps symbolizing a divided or fractured state.

This flag is a work of fiction created by the Kaiser Cat Collective for an alternate history video titled "the German Empire in Vietnam." Its lore is inspired by the popular Kaiserreich: Legacy of the Weltkrieg universe, in which the German Empire survives past World War I. According to the scenario presented, this flag represents a failing monarchist regime in South Vietnam, propped up by the German monarchy during a three-way Cold War. The design serves as the national banner for this specific, fictional Vietnamese state within that alternate timeline.