| Name | Birth date | Relationship with Floyd Williams |
| Knut, Horda King Of Denmark | WFT Est. 732-769 | 38th great-grandfather |
| Lacey, Charles Christian | WFT Est. 1766-1786 | Husband of the 4th great-grandaunt |
| Lacey, Mary E. | WFT Est. 1800-1811 | 1st cousin 5 times removed |
| Lackland | December 24, 1167 | 25th great-grandfather |
| | | Half 5th cousin 27 times removed |
| | | 8th cousin 27 times removed |
| | | 9th cousin 28 times removed |
| | | 10th cousin 26 times removed |
| | | 11th cousin 26 times removed |
| | | 10th cousin 28 times removed |
| | | 11th cousin 27 times removed |
| Lacy, Mary | 1776 | Wife of the 4th great-grandfather |
| | | Wife of the 4th great-granduncle |
| Lacy, Polly | 1776 | Wife of the 4th great-grandfather |
| | | Wife of the 4th great-granduncle |
| Lairach, Duach, Prince | WFT Est. Bef. 100 | 81st great-grandfather |
| | | 85th great-grandfather |
| Lawha, Modha | WFT Est. Bef. 127 | 62nd great-grandfather |
| | | 9th cousin 68 times removed |
| Le Gros., Pepin | WFT Est. 546-647 | 40th great-grandfather |
| LeBrun, Elizabeth | WFT Est. 1455-1484 | 15th great-grandmother |
| | | Wife of the half 15th cousin 17 times removed |
| | | Wife of the 18th cousin 17 times removed |
| | | Wife of the 19th cousin 18 times removed |
| | | Wife of the 20th cousin 16 times removed |
| | | Wife of the 21st cousin 16 times removed |
| | | Wife of the 20th cousin 18 times removed |
| | | Wife of the 21st cousin 17 times removed |
| LeBrun, Humphrey | WFT Est. 1412-1456 | 16th great-grandfather |
| Lee, Mary | WFT Est. 1511-1550 | 11th great-grandmother |
| | | Wife of the half 19th cousin 13 times removed |
| | | Wife of the 22nd cousin 13 times removed |
| | | Wife of the 23rd cousin 14 times removed |
| Leimeadhain, Lochaidh | WFT Est. 256-322 | 54th great-grandfather |
| | | 21st cousin 52 times removed |
| Leney, Dora A. | September 10, 1867 | 2nd cousin twice removed |
| Leney, Flora E. | December 26, 1878 | 2nd cousin twice removed |
| Leney, John Wallace | March 28, 1822 | Husband of the 1st cousin 3 times removed |
| Leney, Lela | September 11, 1869 | 2nd cousin twice removed |
| Leney, Lola | September 11, 1869 | 2nd cousin twice removed |
| Leney, Mildred Ann | December 7, 1870 | 2nd cousin twice removed |
| Leney, Ollie M. | April 23, 1873 | 2nd cousin twice removed |
| Lewis VI | WFT Est. 1053-1113 | 28th great-grandfather |
| Linn, Elizabeth | Abt. 1819 | 2nd great-grandmother |
| Lleuver Mawr | WFT Est. 122-159 | 56th great-grandfather |
| Lodbrok, Rayner King | WFT Est. 677-713 | 40th great-grandfather |
| Longshanks | June 17, 1239 | 23rd great-grandfather |
| | | Half 7th cousin 25 times removed |
| | | 10th cousin 25 times removed |
| | | 11th cousin 26 times removed |