The Type 100 submachine gun (一〇〇式機関短銃 Hyaku-shiki kikan-tanjū) was a Japanese submachine gun used during World War II, and the only submachine gun produced by Japan in any quantity. It was made in two basic variants referred to by American and British observers as the Type 100/40 and the Type 100/44, the latter also known as the Type 100 (Simplified). A third variant was a folding version of the early model, sometimes referred to as the Type 100 Navy, made for parachutists.