Thomas St Aubyn (c. 1578 – 1637) was an English politician.

He was the son of Thomas St Aubyn of Clowance in Cornwall and studied at Queen's College, Oxford and the Middle Temple.^[1]

He was elected the MP for St Ives in the Parliament of 1601 alongside Thomas Barton and MP for Grampound in the Addled Parliament (1614).^[1]

He married Katherine, the daughter of John Bonython of Carclew with whom he had two sons and a daughter.^[1]