The Tsugaru Peninsula (津軽半島 Tsugaru Hantō) is a peninsula in Aomori Prefecture, at the northern end of Honshū island, Japan. The peninsula projects north into the Tsugaru Strait separating Honshū from Hokkaidō. The western coast is on the Sea of Japan, while on its eastern coast are Aomori Bay and Mutsu Bay. Across the Tsugaru strait to the north is Hokkaidō's Matsumae Peninsula, to which it is linked by the Seikan Tunnel.
Traditionally one of the poorest and remotest areas of Japan, Tsugaru is best known as the birthplace of writer Osamu Dazai, who wrote the mordant travelogue Tsugaru about his travels around the peninsula, and for the Tsugaru-jamisen, a distinctive local version of the Japanese string instrument shamisen.