Guillaume III des Pays-Bas
was Japan's first steam-powered warship. It was presented to the Tokugawa shogunate ruling Japan during the Bakumatsu period as a gift from King William III of the Netherlands to assist Janus Henricus Donker Curtius, head of the Nederlandsche Handel-Maatschappij (Netherlands Trading Society) in Japan in his efforts to establish formal diplomatic relations and the opening of Japanese ports to Dutch merchant vessels.