William Tetherly was born about 1661 in Kittery, York Co., Province of Maine, Massachusetts. He died on 18 Dec 1691 in Kittery, York Co., Province of Maine, Massachusetts or in 1693. He was a mariner. He was married to Mary Robie on 13 Aug 1683 in Portsmouth, Rockingham Co., New Hampshire.

Mary Robie was born about 1666. She died after 1699. Children were:

i. Mary Tetherly.
ii. Deacon William Tetherly was born on 3 Nov 1685 in Kittery, York Co., Province of Maine, Massachusetts. He was a shipwright.
iii. Samuel Tetherly was born on 26 Feb 1686/87 in Kittery, York Co., Province of Maine, Massachusetts. He was a shipwright.
iv. Elizabeth Tetherly was born on 20 Jul 1689 in Kittery, York Co., Province of Maine, Massachusetts.
v. Daniel Tetherly was born on 20 Mar 1691 in Kittery, York Co., Province of Maine, Massachusetts. He died in 1757. He was a schoolmaster.

Mary Robie married second John Lydston in 1693.