The Cruiser submarine Type-A (巡潜甲型潜水艦, Junsen Kō-gata sensuikan) was a class of submarine in the Imperial Japanese Navy (IJN), which served during the Second World War.

The Type-A submarines were divided into four classes: Project number S35Ja.

They were equipped with less powerful diesel engines which shortened the time needed to build them.

They had a large hangar and were equipped with bulges to be able to operate 2 × special Aichi M6A1 Seiran attack bombers.

However, all boats were cancelled in late 1943, because the IJN turned its attention to the construction of Type E submarine [ja] (戊型潜水艦, Bo-gata sensuikan) in 1945.