The Voisin III was a French biplane aircraft designed and built by the Voisin brothers in the early years of aviation. It was a significant improvement over earlier Voisin designs and was widely used as a military aircraft during World War I.

The Voisin III was a two-seater biplane with a wooden structure and fabric covering. It was powered by a 100-horsepower Gnôme rotary engine and had a top speed of around 62 miles per hour (100 kilometers per hour). The aircraft was armed with a single machine gun mounted on the upper wing, and could carry up to 220 pounds (100 kilograms) of bombs.

The Voisin III was designed primarily as a reconnaissance aircraft, and was widely used by the French military for this purpose during World War I. However, it was also used as a bomber, with some examples being fitted with up to four machine guns and additional bomb racks.

One of the key innovations of the Voisin III was its use of a box girder structure for the wings, which made them stronger and more rigid than earlier Voisin designs. This, combined with its good stability and ease of handling, made the Voisin III a popular aircraft among pilots.

Overall, the Voisin III was an important aircraft in the early years of aviation, and helped establish the importance of reliable, multirole aircraft designs. It was also a significant contributor to the development of military aviation during World War I.