Akitsushima (秋津洲) was a seaplane tender of the Imperial Japanese Navy (IJN), serving during World War II from 1942 until being sunk in September 1944.

In 1938, the IJN wanted to use their large-sized flying boats more effectively, because the Kawanishi H6K was the only aircraft able to hit Pearl Harbor directly from the Marshall Islands.

The IJN intended to accommodate the flying boat by bow-up trim and slope at first, however this plan was cancelled and the Akitsushima class was equipped with a 35-ton crane.

While running sea trials off Wadamisaki, Kobe, Japan, on 21 April 1942 in the aftermath of the Doolittle Raid — which had taken place on 18 April — Akitsushima opened fire on an approaching Japanese transport plane her crew mistook for a United States Army Air Forces B-25 Mitchell medium bomber.

Her repairs were completed on 5 January 1943, and she was dispatched to Kavieng, only to proceed to Jaluit Atoll in February.

In August 1944, she sailed to Kure and Imari, then to Kaohsiung and Manila, finally arriving at Coron Bay on 23 September 1944.