SMS Don Juan d'Austria was an ironclad warship built for the Austro-Hungarian Navy in the 1870s, the second of the three ships of the Kaiser Max class. The ship was purportedly the same vessel that had been laid down in 1861, and had simply been reconstructed. This was a fiction, however; the head of the Austro-Hungarian Navy could not secure funding for new ships, but reconstruction projects were uncontroversial, so he "rebuilt" the three earlier Kaiser Max-class ironclads. Only the engines and parts of the armor plate were reused in the new Don Juan d'Austria, which was laid down in February 1874, launched in December 1875, and commissioned in October 1876. The ship's career was fairly limited, in part due to slender naval budgets that prevented much active use. She made foreign visits and took part in limited training exercises in the 1880s and 1890s. Long since obsolete, Don Juan d'Austria was removed from service in 1904 and used as a barracks ship through World War I. After the war, she sank under unclear circumstances.

Stabilimento Tecnico Triestino (STT) ("Technical Establishment of Trieste") was a private shipbuilding company based in Trieste from the mid-19th to early 20th century, and the most important naval shipbuilding firm of the Austro-Hungarian Empire.