津軽海峡
It is bordered by the Tsugaru Peninsula to the west, the Shimokita Peninsula to the east and north, with an east-west distance of approximately and a north-south distance of approximately at its eastern end, with a total area of approximately . The outlet of the bay is the wide Tairadate Strait which connects Mutsu Bay to the Tsugaru Strait separating the islands of Honshu and Hokkaido. The bay has an average depth of to , with a maximum depth of near its outlet to the Tsugaru Strait.