| Name | Birth date | Relationship with Sean Mulcahey |
| Pauillot, Mar. | Abt. 1695 | 9th great-grandmother |
| Pelletier, Madeleine | Abt. 1660 | 9th great-grandmother |
| Penigaud, Françoise | Abt. 1685 | 8th great-grandmother |
| Penny | | Wife of the 1st cousin once removed |
| | | Wife of the 8th cousin once removed |
| | | Wife of the 9th cousin |
| | | Wife of the 8th cousin twice removed |
| | | Wife of the 9th cousin once removed |
| Pepere | September 30, 1898 | Great-grandfather |
| | | 6th cousin 3 times removed |
| | | 7th cousin twice removed |
| | | 6th cousin 4 times removed |
| | | 7th cousin 3 times removed |
| Pepin, Elisabeth | Abt. 1630 | 9th great-grandmother |
| Pepin, Isab. | Abt. 1660 | 9th great-grandmother |
| Petit, Jeane | | 9th great-grandmother |
| Petit, Louis | | 8th great-grandfather |
| Petit, Louis | Bef. 1783 | 7th great-grandfather |
| | | Husband of the 8th great-grandaunt |
| Petit, M. G. | | 9th great-grandmother |
| Petit, Marie-Anne | Bef. 1798 | 6th great-grandmother |
| | | 1st cousin 9 times removed |
| | | Wife of the 2nd cousin 8 times removed |
| Petit, Nic. | | 9th great-grandfather |
| Phanef, Antoine-Mathias | Abt. 1745 | 6th great-grandfather |
| Phaneuf, Charlotte | Abt. 1805 | 4th great-grandmother |
| Phaneuf, Paul | Abt. 1775 | 5th great-grandfather |
| Philip | May 24, 1983 | 2nd cousin |
| | | 9th cousin |
| | | 9th cousin once removed |
| | | 10th cousin |
| Philomina, Sister | December 05, 1889 | Great-grandaunt |
| | | 6th cousin 3 times removed |
| | | 7th cousin twice removed |
| | | 6th cousin 4 times removed |
| | | 7th cousin 3 times removed |
| Pichon, Marie | Abt. 1610 | 10th great-grandmother |
| Pillard, Catherine | Bef. 1753 | 9th great-grandmother |
| Pinar, Louis | Abt. 1670 | 9th great-grandfather |
| Pinard, Marie-Urs. | Abt. 1700 | 8th great-grandmother |
| Plourde, Matthew Paul | December 06, 1991 | 2nd cousin |
| Plourde, Paul Peter | | Husband of the 1st cousin once removed |
| Pomponniello, Mar. | | 9th great-grandmother |
| Poupard, Elisabeth | | 8th great-grandmother |
| Poupart, René | | 9th great-grandfather |
| Powers, Virginia Louise | October 24, 1916 | Ex-wife of the half 1st cousin twice removed |
| Pricilla | April 21, 1932 | Wife of the granduncle |
| | | Wife of the 7th cousin twice removed |
| | | Wife of the 8th cousin once removed |
| | | Wife of the 7th cousin 3 times removed |