Sir Thomas Arundell of Wardour Castle in Wiltshire (c. 1502 – 26 February 1552) was a Cornish administrator and alleged conspirator.

In late 1551 he temporarily aligned himself with the Protector Somerset, thereby putting himself in conflict with John Dudley, Earl of Warwick.

Thomas Arundell, born about 1502, was the younger of the two sons of Sir John Arundell (1474–1545) of Lanherne, St. Mawgan-in-Pyder, Cornwall, Receiver General of the Duchy of Cornwall and "the most important man in the county",[1] by his first wife, Lady Eleanor Grey (d. by December 1503), the daughter of Thomas Grey, 1st Marquess of Dorset.

Arundell was educated at Lincoln's Inn, and began his career in the household of Cardinal Wolsey, where he was a contemporary of Thomas Cromwell.

He was a Justice of the Peace for Cornwall, Dorset and Somerset during the reigns of Henry VIII and Edward VI, and was appointed to commissions for gaol delivery, oyer and terminer, and the defence of the counties of the south-west coastline.

[3][4] Arundell's role as one of the commissioners for the dissolution of the monasteries in the West Country enabled him to acquire a number of properties formerly belonging to religious houses.

Arundell consistently protested his innocence, but was convicted, beheaded on Tower Hill on 26 February 1552, and buried in the Church of St Peter ad Vincula.