The flag of the British Indian Ocean Territory consists of a blue field with a palm tree above a stylized white and blue wavy line. The palm tree is centered on the hoist side and has six branches, representing the islands of the territory. The flag has an aspect ratio of 10:19 (height to width) and the height of the palm tree is two-thirds the width of the flag. The color codes for the flag are:

• Blue: Pantone 286 C (#00247d)
• White: Pantone White (#FFFFFF)

There are no specific measurements provided for the size of the palm tree or the wavy line.