William Bennett was the son of Deliverence Bennett and Mary Bigg. He was born on January 8, 1708/09 in Fairfield, Fairfield County, Connecticut. He died on September 16, 1772 in Westport, also in Fairfield County, Connecticut. His gravestone lists his age as 62 years, 7 months, and 26 days. His will was dated August 5, 1772 and was proved on October 6, 1772.
William Bennett ran a grist mill.

William Bennett and Abigail Hickock were married in August on 1733 in Connecticut. They had the following children (all baptized in Westport, Fairfield County, Connecticut):

Sarah (17 Mar 1733/4 - bet 31 Dec 1776 and 16 Feb 1797) m Jabez Lockwood
Thaddeus (22 Jun 1736 - 20 Jan 1823) m. Mary Platt
Deliverance (27 Feb 1738 - 7 Mar 1808) m. Mary Benedict
William (5 Jul 1741 - 15 Oct 1760)
Mary (25 Aug 1743 - 4 Oct 1754)
Joseph (17 Sep 1745 - 19 Nov 1819) m1. Sarah Lyon, m2. Abigail Sherwood
Stephen (18 Dec 1747 - 5 Sep 1802) m1. Elizabeth _____, m2. Mary _____, m3. Lucy Barnum
Abigail (30 Dec 1749 - aft 16 Feb 1797) m. Samuel Smith

In his will, William Bennett mentions wife, Abigail; sons Thaddeus, Deliverence, Joseph and Stephen; and daughters, Sarah and Abigail. On December 31, 1776, receipts were filed from Samuel and Abigail Smith, and Jabez and Sarah Lockwood, for portions from their father's estate.
In her will, Abigail Morehouse mentions sons Thaddeus and Deliverance Bennett, land in Wilton, and daughter Abigail Smith. It is unclear why Joseph and Stephen were not mentioned.