A coat of arms was granted by the College of Arms in 1961. The emblem of the town used to be a pair of clasped hands symbolising union. This has been included in the coat of arms.

The coat of arms of the Municipality is as much artistic as symbolic. On the blue background (the sea) adorned with “fleurs de lys” (for the patron Saint of the City – St. Louis) are set four white anchors (the port) placed in the form of a cross not only in reference to the four corners of the world to and from which commerce flows in and out of Mauritius but also in reference to the ecclesiastical importance of Port Louis.

On the shield appears a golden mural crown - emblem of civic dignity. The crown contains the former emblem of Union - the clasped hands. The supporters are two sea horses, emblems of transport by sea. The sinister beast supports a palm branch and the dexter supports a sugar cane in reference to the sugar industry in Mauritius, export of sugar being a very important activity of the port.