Sir Thomas Proby, 1st Baronet (18 October 1632 – 22 April 1689) was an English politician who sat in the House of Commons between 1660 and 1685.
Proby was the son of Sir Heneage Proby of Elton Huntingdonshire and his wife Ellen Allen, daughter of Edward Allen, of Finchley, Middlesex.
In 1660, Proby was elected Member of Parliament for Amersham in the Convention Parliament. He was re-elected MP for Amersham in the Cavalier Parliament and sat until 1679. He was created a baronet in 1662. In 1679 he was elected MP for Huntingdonshire and sat until 1685.
Proby died at the age of 56.
Proby married Frances Cotton, daughter of Sir Thomas Cotton, 2nd Baronet of Connington, Huntingdonshire. His daughter Alice married the Hon. Thomas Watson-Wentworth MP, and had an only child, Thomas Watson-Wentworth, 1st Marquess of Rockingham. Proby's son died travelling and the baronetcy became extinct on Proby's death. The Elton estate passed to his brother John Proby.