Born to William Carus and Isabel Leyburn of Westmorland, he joined the Middle Temple in the 1530s and became Member of Parliament for Wigan in 1547. Carus also represented Lancaster in Parliament in 1553 and 1555, became a Serjeant-at-Law in April 1559, and was made a Justice of the Queen's Bench on 31 May 1567. He held this position until his death on 5 July 1571. He was knighted in 1567.
He married Catherine, the daughter of Thomas Preston of Preston Patrick, Westmorland. They had three sons and three daughters. He was initially succeeded by his eldest son Thomas, who soon also died. He was eventually succeeded by his youngest son Christopher.
- Baker, J. H. (2004). "Oxford DNB article: Carus, Thomas (subscription needed)". Oxford University Press. Retrieved 3 March 2011.
|Wikisource has the text of the 1885–1900 Dictionary of National Biography's article about Carus, Thomas.|