Thomas Southworth was born 1676 in Duxbury, Plymouth County, Massachusetts to Edward Southworth (1640-1719) and Mary Pabodie (1648-1728) and died 2 September 1743 Duxbury, Plymouth County, Massachusetts of unspecified causes. He married Sarah Alden (1681-1738) 1701 in Duxbury, Plymouth County, Massachusetts.
Children
| Name | Birth | Death | Joined with |
| Jedediah Southworth (1702-1739) | |||
| Mary Southworth (1703-1735) | |||
| Nathaniel Southworth (1711-1731) | |||
Siblings
| Name | Birth | Death | Joined with |
| Mercy Southworth (1670-1728) | |||
| Thomas Southworth (1676-1743) | 1676 Duxbury, Plymouth County, Massachusetts | 2 September 1743 Duxbury, Plymouth County, Massachusetts | Sarah Alden (1681-1738) |
| Benjamin Southworth (1681-1756) | 1681 Duxbury, Plymouth County, Massachusetts | 12 May 1756 Duxbury, Plymouth County, Massachusetts | Rebecca Delano (1684-1771) |