The flag of the French Southern and Antarctic Lands consists of a horizontal tricolor design with three equal bands: blue (#0055A4) on the top, white (#FFFFFF) in the middle, and red (#EF4135) at the bottom. In the white band, there is a small version of the French flag in the canton (upper hoist-side corner), with dimensions of 1/3 the width of the white stripe. Beside the French flag, there is the territory's coat of arms, which takes up approximately half the height of the white stripe.

The aspect ratio of the flag is 2:3, meaning it is twice as wide as it is tall. Unfortunately, exact geometric properties and measurements are not readily available for this flag.