| Celebration | Name | Saint | Birth | Death |
|---|---|---|---|---|
| 12 of December | Mercuria | Saint Mercuria | ||
| 13 of December | Mardario | Saint Mardario | ||
| 14 of December | Matroniano | Saint Matroniano | ||
| 15 of December | María | Blessed Maria Victoria Fornari | Italy | 1617 Italy |
| 15 of December | Marino | Blessed Marino | 1170 | |
| 15 of December | María | Saint María Crucificada of Rosa | Italy | 1855 Italy |
| 15 of December | Maximino | Saint Maximino abad | France | France |
| 16 of December | Macario | Saint Macario of Collesano | Italy | 1005 Italy |
| 16 of December | María | Blessed Mary of the Angels (Mariana) Fontanella | Italy | 1717 Italy |
| 17 of December | Modesto | Saint Modesto obispo | Israel | 634 Israel |
| 18 of December | Malaquías | Saint Malaquías | Israel | Israel |
| 20 of December | Michal | Blessed Michal Piaszczynski | Poland | 1940 Poland |
| 20 of December | Macario | Saint Macario sacerdote y mártir | ||
| 21 of December | Miqueas | Saint Miqueas profeta | Israel | Israel |
| 23 of December | María | Saint María Margarita of Youville | 1701 Canada | 1771 Canada |
| 24 of December | Metrobio | Saint Metrobio mártir | ||
| 25 of December | Michael | Blessed Michael Nakasima | 1628 Japan | |
| 28 of December | Matías | Blessed Matthia of Nazareis | 1326 Italy | |
| 30 of December | Margarita | Blessed Margaret Colonna | 1280 Italy | |
| 31 of December | Melania | Saint Melania the Younger | 383 Italy | 439 Israel |
| 31 of December | Mario | Saint Mario obispo | 594 Switzerland |