Sir Thomas Monson, 1st Baronet, of Carlton (1565 – 29 May 1641) was an English politician and supporter of King James I.

Thomas was educated at Magdalen College, Oxford, matriculating at the age of fifteen in December 1579, and at Gray's Inn, where he was admitted a student in 1583.

Sir Thomas was appointed a Justice of the Peace in 1592 and High Sheriff of Lincolnshire for 1597 and probably knighted the same year.

He was made Chancellor of the English jointure lands of the king's wife Anne of Denmark in 1603.

But in 1615 his position of trust at the Tower of London brought about a situation which led to his arrest as one of the participators in the 1613 murder of Sir Thomas Overbury.