No date of birth is known; it is likely that he was born before 1563 based on the date of his marriage and the birth of his children.
From "The History of the Hunt Family" book in the chapter, "Clayton and Beals Families," it is shown that records in the parish archives show that “Rychard Cleton” married, in Walberton, Essex, England, Dorothy “Burkenshall” (more often spelled Birkenshaw), on 24 January 1582. Richard and Dorothy were both buried in Walberton: Richard on 13 January 1615 and Dorothy on 15 January 1613.
In the parish archives, the following children of Richard and Dorothy can be found:
i. Richard Clayton - Baptized 24 Apr 1583, Richard Jr. married Elizabeth Peter at Walberton on 16 Dec 1610.
ii. John Clayton - Baptized 26 Jan 1586. John died at age 13 and was buried at Walberton on 7 Jun 1597, “son of Richard Cleton.”
iii. William Clayton - Baptized 24 Feb 1589 at Walberton.
iv. Lawrence Clayton - Baptized 25 Nov 1593. No further information.
Quaker genealogist James Bellarts published an erroneous ancestry for the Clayton family of Sussex. Rychard's son, grandson, and great-grandson are all named William and are all from Sussex (Walberton and Boxgrove). The Bellarts line shows William the grandson as a son of a Yorkshire William Clayton and his father as a Thomas Clayton from a supposed noble family. This link has been proven to be incorrect. "Other research by Col. Charles M. Hansen, Louis E. Jones and Marilyn L. Winton-Misch has shown that William Clayton, the immigrant ancestor, was not related to the Yorkshire family of that name."