This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. Find sources: "Thomas Ros, 8th Baron Ros" – news · newspapers · books · scholar · JSTOR (September 2014) (Learn how and when to remove this message)

Thomas Ros or Roos, 8th Baron Ros of Helmsley (26 September 1406 – 18 August 1430) was an English peer.

Thomas Ros, born 26 September 1406, was the second son of William Ros, 6th Baron Ros, and Margaret Fitzalan (d. 3 July 1438), the daughter of John FitzAlan, 1st Baron Arundel, by Eleanor Maltravers (c.1345 – 12 January 1405), younger daughter and coheir of Sir John Maltravers (d. 22 January 1349).^[2]

Thomas Ros was a younger brother of John Ros, 7th Baron Ros, who died childless at the Battle of Baugé on 22 March 1421. Thomas inherited his rank and privileges, and followed the example of his brother in participating in the Hundred Years' War. He fought in the Battle of Verneuil under the command of John, Duke of Bedford. He was honoured for his efforts, and knighted by Henry VI of England on 19 May 1426. Henry was a nephew of the Duke. Thomas resumed service under the Duke in 1427. He was summoned to the Parliament of England in 1429. In 1430, he fell into the Seine during a minor skirmish and drowned.

Thomas Ros married Eleanor Beauchamp, daughter of Richard Beauchamp, 13th Earl of Warwick, and his first wife, Elizabeth Berkeley, by whom he had two sons and a daughter:^[3]

• Thomas Ros, 9th Baron Ros (9 September 1427 – 17 May 1464).
• Sir Richard Ros, who married, before 1468, Jane or Joan Knyvet, daughter of Sir John Knyvet.^[4]
• Margaret Ros, who married firstly William de Botreaux, 3rd Baron Botreaux, and secondly Thomas Burgh, 1st Baron Burgh of Gainsborough.

After the death of Thomas Ros, his widow, Eleanor, married secondly, Edmund Beaufort, 1st Duke of Somerset, and thirdly, Walter Rokesley, esquire.^[5]

• Cokayne, George Edward (1949). The Complete Peerage, edited by Geoffrey H. White. Vol. XI. London: St. Catherine Press.
• Richardson, Douglas (2011). Magna Carta Ancestry: A Study in Colonial and Medieval Families, ed. Kimball G. Everingham. Vol. I (2nd ed.). Salt Lake City.{{cite book}}: CS1 maint: location missing publisher (link) ISBN 1449966373
• Richardson, Douglas (2011). Magna Carta Ancestry: A Study in Colonial and Medieval Families, ed. Kimball G. Everingham. Vol. III (2nd ed.). Salt Lake City.{{cite book}}: CS1 maint: location missing publisher (link) ISBN 144996639X