| Martirio | | mahr-TEE-ryo | Spanish | |
| Martita | | mahr-TEE-tah | Spanish | |
| MatÍAs | | - | Spanish | |
| Mateo | | mah-TE-o (Spanish) | Spanish, Croatian | |
| Matilde | | mah-TEEL-de (Spanish) | Spanish, Portuguese, Italian | |
| Maura (1) | | MOW-rah (Italian, Spanish) | Italian, Spanish, Late Roman | |
| Mauricio | | mow-REE-thyo (Spanish), mow-REE-syo (Latin American Spanish) | Spanish | |
| Maximiano | | mahk-see-MYAH-no (Spanish) | Spanish, Portuguese | |
| Maximiliano | | mahk-see-mee-LYAH-no (Spanish) | Spanish, Portuguese | |
| Maximino | | mahk-see-MEE-no (Spanish) | Spanish, Portuguese | |
| Mayra | | - | Spanish (Latin American), American (Hispanic) | |
| Mayte | | - | Spanish | |
| Melania | | me-LAHN-yah (Polish) | Italian, Spanish, Polish, Late Roman | |
| Melchor | | mel-CHOR | Spanish | |
| Melisa | | - | Spanish, Bosnian | |