The flag of Saint Pierre and Miquelon has an aspect ratio of 2:3. It is divided into three vertical bands: the left band (blue) occupying one-third of the flag's width, and the remaining two-thirds split equally between a red band and a white square.

In the blue band, there are two yellow squares in the top-right and bottom-left corners, each with a side length of 1/8th the flag's height. The red band features a narrow white horizontal stripe running through its center, with a height of 1/20th the flag's height.

Color codes for the flag are:

• Blue: #002395
• Red: #ED2939
• White: #FFFFFF
• Yellow: #FCD116