Ambanja is a district in northern Madagascar. It is a part of Diana Region and borders the districts of Ambilobe to the east, Bealanana to the south and Analalava to the south-west. The area is and the population was estimated at 190,435 in 2013.
The district is the main producer of Cocoa beans (valley of the Sambirano River) in Madagascar.
The district is further divided into 18 communes: