- M:me Tingley (1970)
- Maasdam (1952)
- Maaninka (1919)
- Malmö (1969)
- Marburg (1966)
- Marconi (1992)
- Marieholm (1934)
- Marin (1956)
- Marina Master (1988)
- Marine (1956)
- Marine Princess (1993)
- Mariner VI (1956)
- Marittima (1958)
- Mariya Ermolova (1974)
- Marlin (1956)
- Marnix Van Sint-Aldegonde (2021)
- Mecklenburg (1960)
- Mecklenburg (2003)
- Merilin (1999)
- Meteor 2 (1992)
- Midnatsol (1949)
- Midnatsol 2 (1949)
- Midnatsol Norge (1949)
- Mikkeli (1919)
- Misisipi (1988)
- Moby Dick (1958)
- Moby Dick (1966)
- Moby Dick I (1958)
- Motala Ström (1916)
- MSC Irbis (1990)
- My Master (1988)
- Mälar Victoria (1984)
- Möltenört (1963)