[2] In 1704, Pitt married Harriet Villiers,[3] the daughter of Edward Villiers-FitzGerald and the Irish heiress Katherine FitzGerald.
In 1705 Pitt was returned as Member of Parliament for Old Sarum, a pocket borough controlled by his family.
He retained the seat at the 1708 general election, but in 1710 was not put forward by his father and was returned instead on his own account as MP for Salisbury.
He came third in the poll at Salisbury at the 1713 general election but his father then put him up at Old Sarun again where he was returned.
His second son was William Pitt the Elder, a British statesmen who led the country three times in 1756–57, 1757–1762 and 1766–1768.