Marius may refer to:
- Marius (name), a male given name, a Roman clan name and family name, and a modern name or surname
- Gaius Marius (157–86 BC), Roman general and statesman
- Gaius Marius the Younger (110-82 BC), his son, also a general and statesman
- Simon Marius (1573–1625), German astronomer, known for independently discovering and naming the four major moons of Jupiter
- Other men from the Roman gens Maria
- Marcus Aurelius Marius (died 269), emperor of the Gallic Empire in c. 269 AD
- Marius Clore FRS (1955-), Anglo-American molecular biophysicist and structural biologist
- Marius Pontmercy, a fictional character in Victor Hugo's novel Les Misérables
- Marius (crater), on the Moon
- Marius Hills, on the Moon
- Marius (1931 film), a French film directed by Alexander Korda and written by Marcel Pagnol
- Marius (2013 film), a 2013 film adaptation of the play by Marcel Pagnol
- "Marius" (Anderson), a science fiction story by Poul Anderson
- Măriuș, a village in Valea Vinului commune, Satu Mare County, Romania
- Marius (Laconia), a town of ancient Laconia, Greece
- Marius (giraffe), a giraffe that drew controversy against the Copenhagen Zoo for being put down in early 2014
See also
- All pages with titles containing Marius
- All pages with titles beginning with Marius
- Mario (disambiguation)
- Maria (disambiguation)
- Mary (disambiguation)