SMS Viribus Unitis  was an Austro-Hungarian dreadnought battleship, the first of the Tegetthoff class. "Viribus Unitis", meaning "With United Forces", was the personal motto of Emperor Franz Joseph I.

The Tegetthoff class was a class of four dreadnought battleships built for the Austro-Hungarian Navy. Named for Austrian Admiral Wilhelm von Tegetthoff, the class was composed of SMS Viribus Unitis, SMS Tegetthoff, SMS Prinz Eugen, and SMS Szent István. Construction started on the ships shortly before World War I; Viribus Unitis and Tegetthoff were both laid down in 1910, Prinz Eugen and Szent István followed in 1912. Three of the four warships were built in the Stabilimento Tecnico Triestino shipyard in Trieste; Szent István was built in the Ganz-Danubius shipyard in Fiume, so that both parts of the Dual Monarchy would participate in the construction of the ships. The Tegetthoff-class ships hold the distinction for being the first and only dreadnought battleships of the Austro-Hungarian Navy. The SMS Szent István had a different more modern propulsion system than her sister ships.