Dumanquilas Bay (alternatively spelled Dumanguilas Bay) is an arm of the Moro Gulf on the southern side of the Zamboanga Peninsula in western Mindanao island in the Philippines.

It is known for its extensive mangrove shorelines and rich coral and fish diversity.

[2] Dumanquilas Bay covers an area of about 26,000 hectares (64,000 acres) with depths of between 12 and 120 feet (3.7 and 36.6 m).

[3] The bay contains several small islands, the largest of which is Igat Island located on its eastern side in Margosatubig municipality which forms the western border of a small inlet called Igat Bay.

On the Zamboanga Sibugay side are Muda, Dacula and Paya islands.