| Name | Birth date | Relationship with Sean Mulcahey |
| Mongeau, Pierre-J. | | 9th great-grandfather |
| Moorehead, Mary Ellen | 1848 | 3rd great-grandmother |
| Moorehead, Michael | Abt. 1830 | 4th great-grandfather |
| Moorehead, Sister | | 3rd great-grandaunt |
| Moreland, Eileen Nancy | November 25, 1966 | Wife of the 2nd cousin once removed |
| Morin, Agnès | | 9th great-grandmother |
| Morin, Anne | Abt. 1690 | 8th great-grandmother |
| Morin, Pierre-X. | Abt. 1660 | 9th great-grandfather |
| Mulcahey, Barbara A. | | Half 2nd cousin once removed |
| Mulcahey, Brian David | October 10, 1964 | Uncle |
| Mulcahey, Colleen Louise | July 20, 1994 | Sister |
| | | 9th cousin |
| | | 9th cousin once removed |
| | | 10th cousin |
| Mulcahey, Daniel | | Half 1st cousin twice removed |
| Mulcahey, Elizabeth H. | December 21, 1895 | Half great-grandaunt |
| Mulcahey, Helen | | Half 1st cousin twice removed |
| Mulcahey, Irene | | Half 1st cousin twice removed |
| Mulcahey, Joseph Kevin | June 18, 1961 | Father |
| | | 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 |
| Mulcahey, Kathleen Ann | January 01, 1967 | Aunt |
| Mulcahey, Martin | September 03, 1899 | Great-grandfather |
| Mulcahey, Mary Agnes | August 06, 1893 | Half great-grandaunt |
| Mulcahey, Maureen E. | | Half 2nd cousin once removed |
| Mulcahey, Patrick | Bef. 1850 | 3rd great-grandfather |
| Mulcahey, Raymond | | Half 1st cousin twice removed |
| Mulcahey, Rita | | Half 1st cousin twice removed |
| Mulcahey, Robert Leo | July 13, 1937 | Grandfather |
| Mulcahey, Sean Robert | September 14, 1991 | Self |
| | | 9th cousin |
| | | 9th cousin once removed |
| | | 10th cousin |
| Mulcahey, Sharon M. | | Half 2nd cousin once removed |
| Mulcahey, Thomas | | Half 1st cousin twice removed |
| Mulcahey, Thomas | January 21, 1890 | Half great-granduncle |
| Mulcahey, Wife | | Wife of the half great-granduncle |
| Mulcahey, William | Abt. 1859 | 2nd great-grandfather |
| Mulcahey, William L. | | Half 2nd cousin once removed |
| Mulcahey, William L. | June 06, 1921 | Half 1st cousin twice removed |
| Mulcahey, William T. | August 02, 1891 | Half great-granduncle |
| Muldoon, Glenn | | 3rd cousin |
| | | 9th cousin |
| | | 9th cousin once removed |
| | | 10th cousin |
| Muldoon, Gordon | | Husband of the 2nd cousin once removed |
| | | Husband of the 8th cousin once removed |
| | | Husband of the 9th cousin |