The flag of Saint Barthélemy has an aspect ratio of 2:3. It consists of three horizontal stripes with the following colors and proportions:

1. Top stripe: Blue (#002395) - occupies 1/3 of the flag's height.
2. Middle stripe: White (#FFFFFF) - occupies 1/3 of the flag's height.
3. Bottom stripe: Red (#ED2939) - occupies 1/3 of the flag's height.

On the left side of the white stripe, there is a simplified version of the coat of arms of Saint Barthélemy, which is a shield with the Maltese cross in the upper-left corner and three fleurs-de-lis in the other quadrants. The shield is surrounded by a laurel wreath.