He inherited Crowland Abbey, Lincolnshire, as part of the estate of the last of the Orby baronets.
From December 1758 till April 1760, he was superintendent of supplies to the allied armies in Germany and Lord of the Treasury from April 1763 till July 1765.
In 1746, Hunter became chief at William Pitt the Elder's pay office.
On 27 February 1767, he voted against the Chatham ministry on the land tax.
At the 1768 general election, he aligned himself with Lord Thomond's Egremont policies, On 4 April 1749, he married Jacomina Caroline Bullenden, the daughter of Colonel William Bullenden.