| Name | Birth date | Relationship with Sean Mulcahey |
| Lian, Julie | | Wife of the 2nd cousin once removed |
| Libby, Joanne Lynn | January 19, 1979 | 2nd cousin |
| Libby, John Philip | July 20, 1948 | Ex-husband of the 1st cousin once removed |
| Libby, Michael John | May 13, 1980 | 2nd cousin |
| Libby, Michelle Marie | July 17, 1976 | 2nd cousin |
| Lisa | | 2nd cousin |
| | | 9th cousin |
| | | 9th cousin once removed |
| | | 10th cousin |
| Loi, Devon | | Half 3rd cousin |
| Loisel, Joseph | | 9th great-grandfather |
| Loisel, Marie-Madeleine | | 8th great-grandmother |
| Lorion, Renée | | 9th great-grandmother |
| Lou, Mary | | 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 |
| Louis | | Wife of the great-granduncle |
| Lussier, Christian | | 6th great-grandfather |
| Lussier, Christian | | 8th great-grandfather |
| Lussier, Madeleine | Bef. 1828 | 4th great-grandmother |
| | | 3rd cousin 6 times removed |
| | | 4th cousin 5 times removed |
| | | 4th cousin 6 times removed |
| | | Wife of the 3rd cousin 7 times removed |
| | | Wife of the 4th cousin 6 times removed |
| Lussier, Paul | | 7th great-grandfather |
| Lussier, Pierre | Bef. 1813 | 5th great-grandfather |
| | | Husband of the 2nd cousin 7 times removed |
| | | Husband of the 3rd cousin 6 times removed |
| | | Husband of the 3rd cousin 7 times removed |
| Lussyé, Jacques | | 9th great-grandfather |
| Lynch, Andrew James | November 26, 1967 | Husband of the 1st cousin once removed |
| | | Husband of the 8th cousin once removed |
| | | Husband of the 9th cousin |
| | | Husband of the 8th cousin twice removed |
| | | Husband of the 9th cousin once removed |
| Lynch, Brittany K. | January 23, 1991 | 3rd cousin |
| Lynch, Courtney Elizabeth | July 07, 1989 | 3rd cousin |
| Lynch, Kevin F. | | Husband of the 2nd cousin once removed |
| M., Mary | 1834 | 3rd great-grandmother |
| MacLean, Flora | Abt. 1850 | 3rd great-grandmother |
| Magneron, Marie-Josephte | Bef. 1798 | 6th great-grandmother |
| | | 2nd cousin 8 times removed |
| | | Wife of the 1st cousin 8 times removed |
| | | Wife of the 2nd cousin 8 times removed |
| Mailloux, Anne | Abt. 1630 | 9th great-grandmother |
| Manosh, Sandy | November 30, 1952 | Wife of the 1st cousin once removed |
| | | Wife of the 8th cousin once removed |