The No.1-class submarine chaser (第一号型駆潜特務艇,, Dai Ichi Gō-gata Kusen-Tokumutei) was a class of auxiliary submarine chasers of the Imperial Japanese Navy (IJN), serving during World War II.

(Other contemporary Japanese harbour tugs were powered by compound steam engines).

They had wooden hulls and were designed so that they could be converted to fishing boats after hostilities ended.

Their wartime performance was good, but they were always troubled by insect damage because their hull was wooden.

Those that survived the war played an active part in the sweeping of magnetic mines in company with the No.1-class auxiliary patrol boats.