| Name | Birth date | Relationship with Floyd Williams |
| Caesar, Lucius Julias | WFT Est. Bef. 100 | 68th great-grandfather |
| Caesar, Numerius Julias | WFT Est. Bef. 100 | 69th great-grandfather |
| Caesar, Sextus Julias | WFT Est. Bef. 100 | 66th great-grandfather |
| Caesar, Sextus Julias | WFT Est. Bef. 100 | 67th great-grandfather |
| Caisfhiaclach, Oiliolla, 77Th King | WFT Est. Bef. 100 | 74th great-grandfather |
| | | 78th great-grandfather |
| Caledomir | WFT Est. Bef. 100 | 77th great-grandfather |
| Campbell, Alexander | 1822 | Great-granduncle |
| Campbell, John Poage | WFT Est. 1762-1782 | Husband of the 3rd great-grandaunt |
| Campbell, Mark | Abt. 1800 | 2nd great-grandfather |
| Campbell, Martha | 1829 | Great-grandmother |
| Campbell, Sarah | WFT Est. 1786-1806 | Wife of the 3rd great-granduncle |
| Caolbreagh, Cobblach, 69Th King | WFT Est. Bef. 100 | 78th great-grandfather |
| | | 82nd great-grandfather |
| Capoir | WFT Est. Bef. 100 | 65th great-grandfather |
| Carlson, Agnes | 1898 | Aunt |
| Carlson, Billie | October 21, 1907 | Mother |
| Carlson, Claude V. | 1909 | Uncle |
| Carlson, David Edward | December 11, 1902 | Uncle |
| Carlson, Ella Elizabeth | February 4, 1904 | Aunt |
| Carlson, Emma V. | August 6, 1906 | Aunt |
| Carlson, John W, Jr. | 1911 | Uncle |
| Carlson, John W. | 1863 | Grandfather |
| Carlson, Joseph Harold | February 10, 1915 | Uncle |
| Carlson, Laura F. | Private | Aunt |
| Carlson, Sadie Louise | October 21, 1907 | Mother |
| Carlson, Thomas F. | March 20, 1909 | Uncle |
| Caroline | 1683 | Wife of the 14th cousin 10 times removed |
| | | Wife of the half 22nd cousin 10 times removed |
| Cassander | WFT Est. Bef. 100 | 70th great-grandfather |
| Castile, Eleanor Of | WFT Est. 1220-1243 | 23rd great-grandmother |
| | | Wife of the half 7th cousin 25 times removed |
| | | Wife of the 10th cousin 25 times removed |
| | | Wife of the 11th cousin 26 times removed |
| | | Wife of the 12th cousin 24 times removed |
| | | Wife of the 13th cousin 24 times removed |
| | | Wife of the 12th cousin 26 times removed |
| | | Wife of the 13th cousin 25 times removed |
| Cave, Nancy | 1798 | Wife of the 3rd great-granduncle |
| Cave, Susan Mosley | WFT Est. 1794-1825 | Wife of the 3rd great-granduncle |
| Ceadchadhach, Con | WFT Est. Bef. 127 | 60th great-grandfather |
| | | 15th cousin 58 times removed |
| Charlemagne, King Of The Franks, Roman | April 2, 742 | 38th great-grandfather |
| Charles I King Of England | Abt. 1598 | 11th cousin 13 times removed |
| | | Half 19th cousin 13 times removed |
| | | 22nd cousin 13 times removed |
| | | 23rd cousin 14 times removed |
| Charles II King Of England | Abt. 1625 | 12th cousin 12 times removed |
| | | Half 20th cousin 12 times removed |
| | | 23rd cousin 12 times removed |