[1] Foley was returned unopposed as Member of Parliament for Herefordshire at a by-election on 18 May 1767 and retained his seat at the 1768 general election.
At the 1774 general election he was returned as MP for the family borough of Droitwich until he succeeded to his father's peerage in 1777.
In November 1775 George Selwyn wrote "Old Foley pays another £70,000 of debt, and settles, I hear today, £4,000 in present upon his son, and £6,000 a year more at his death."
[1] The family estate at Stoke Edith had been entailed to Foley under his parents' marriage settlement, but both he and his next brother, Edward, were profligate spenders.
On 20 March 1776, Foley married Lady Henrietta Stanhope (1750–1781), fourth daughter of William Stanhope, 2nd Earl of Harrington and the former Lady Caroline FitzRoy (eldest daughter of Charles FitzRoy, 2nd Duke of Grafton).
After Foley's death, his son Thomas commissioned Nash to add porticoes to the north and south sides of Witley Court.