Mary de Clifford was born circa 1416 in Appleby, Westmoreland, England, United Kingdom to John Clifford, 7th Baron de Clifford (1388-1421) and Elizabeth Percy (c1395-1436) and died 4 October 1478 of unspecified causes. She married Philip Wentworth (1424-1464) 1447 JL in Skelton, Yorkshire, England, United Kingdom.
Children
| Name | Birth | Death | Joined with |
| Henry Wentworth (c1448-1501) | 1448 | 27 February 1501 | Anne Say (1453-1494) Elizabeth Nevill (1464-1517) |
| Elizabeth Wentworth (1420-?) | 1420 | Martin de la See (1420-1494) | |
| Margaret Wentworth (-1479) | |||
Footnotes (including sources)
| ‡ General |