Marcus is a given name that can refer to:
- Marcus Belby, a Ravenclaw student considered for the Slug Club
- Marcus Fenwick, a Ravenclaw student at Hogwarts in the 1990s
- Marcus Flint, the Captain of the Slytherin Quidditch team in the 1990s
- Marcus Hitchin, a Ravenclaw student at Hogwarts in the 1990s
- Marcus Minugius, presumed owner and/or founder of Marcus Minugius Myomancer
- Marcus Morhaven, a student at Hogwarts in the 21st century
- Marcus Turner, a Ravenclaw student at Hogwarts in the 1990s