The Canon de 138 mm Modèle 1927 was a medium-calibre gun of the French Navy used during World War II.

The 40-calibre Mle 1927 was derived from the German World War I 15 cm L/45 UToF gun as mounted on the large torpedo boat SMS S113 received by France as war reparations.

It copied the German gun's semi-automatic action and its horizontal sliding-block breech.

The mount could depress -10° and elevate to +28° which gave it a maximum range of 16,600 metres (18,200 yd).

[1] The gun had a firing cycle of 4 or 5 seconds with its automatic spring rammer, but the dredger hoists transporting the shells and cartridge cases slowed the rate of fire down to 8-10 rounds per minute.