| Marcianus | | - | Ancient Roman | |
| Marcius | | - | Ancient Roman | |
| Marcus | | MAR-kuws (Ancient Roman, Biblical Latin), MAHR-kəs (English) | Ancient Roman, Biblical Latin, English, Swedish, Norwegian, Danish | |
| Mariana | | mə-RYA-nə (Portuguese), mah-RYAH-nah (Spanish) | Portuguese, Spanish, Romanian, Czech, Ancient Roman | |
| Marianus | | - | Ancient Roman | |
| Marinus | | - | Ancient Roman, Dutch | |
| Marius | | MER-ee-əs (English), MAR-ee-əs (English), MAH-ree-uws (German) | Ancient Roman, Romanian, German, Dutch, Norwegian, Danish, French | |
| Markos | | - | Greek, Ancient Greek, Biblical Greek | |
| Martialis | | - | Ancient Roman | |
| Martinus | | - | Ancient Roman, Dutch | |
| Mathghamhain | | - | Ancient Irish | |
| Mathilda | | mə-TIL-də (English, Swedish) | English, Swedish, Ancient Germanic | |
| Maxentius | | - | Ancient Roman | |
| Maxima | | - | Ancient Roman | |
| Maximianus | | - | Ancient Roman | |