William Tetherly was born about 1597 in Northam, co. Devon, England. He signed his will on 30 Apr 1651. He died between 30 Apr 1651 and 9 Dec 1651 in Kittery, York Co., Province of Maine, Massachusetts. His estate was probated on 9 Dec 1651. He was a mariner. He was married to Christian Thorne on 23 Jan 1618 in Northam, co. Devon, England.

Christian Thorne was born about 1601 in Northam, co. Devon, England. She died before 1636 in Kittery, York Co., Province of Maine, Massachusetts. Children were:

i. William Tetherly was a transatlantic sea captain.
ii. Gabriel Tetherly
iii. Ann Tetherly.
iv. John Tetherly was born before 1638. He was a mariner.
v. Mary Tetherly was married to John Garde.

William Tetherly married second Mary Harges in 1636.