Gabriel Gruber, S.J. (May 6, 1740 – April 7, 1805) was the second Superior General of the Society of Jesus in Russia.
Gruber, born in Vienna, became a Jesuit at the young age of 15, in 1755 and did most of his formation and studies in Austria: Latin and Greek in Leoben (1757–1758), theology, philosophy and mathematics in Graz (1758–60), languages in Vienna (1760–61), mathematics in Trnava, Slovakia (1761–62), and again theology in Vienna (1763–67). In 1766, he was ordained priest in Graz.
Gruber was an expert in hydrotechnology and architecture, and had also a basic knowledge of navigation and the history of seamanship.
In early life, Gruber was a fanatical builder of model ships, and some of the teaching materials at the School of Mechanical Engineering were naval models of his that were made at the school between 1774 and 1783. Before being included in the Maritime Museum of Piran collection, these models were kept in the National Museum in Ljubljana. Some of Gruber's other workshop models had been in Pula, Croatia, but disappeared during the withdrawal of the Italian Army in 1943. Other Gruber models exhibited in the Maritime Museum are the Venetian battle galleon, the lagoon cargo galleon, the corvette, the schooner and a framework used during ship construction.