Mare Nostrum (Our Sea in Latin), is an affectionate Roman name for the Mediterranean Sea. It can also refer to:

• Mare Nostrum, a 2003 board game by Serge Laget .
• Mare Nostum, a 1983 board wargame in the Fronte Mare series.
• Mare Nostrum, a 1926 silent film.
• MareNostrum, the most powerful supercomputer in Europe, as of April 2005.