George II Treby (c. 1684–1742) of Plympton House, Plympton St Maurice, Devon, was an English Whig politician, Secretary at War from 1718 to 1724, and Master of the Household from 1730 to 1740. He built Plympton House in c. 1715–20, commenced by his father but unfinished at the latter's death in 1700.
He was the son of Sir George I Treby (d.1700), Lord Chief Justice of the Common Pleas, by his third wife Dorothy Grainge.
He was elected Member of Parliament for the family's Rotten Borough of Plympton Erle in 1708, when he was in his early twenties. He held the seat until 1727, when he became member for Dartmouth, which seat he held until his death.
Treby held a number of posts, including Secretary at War from 1718 to 1724, and Master of the Household from 1730 to 1740. In about 1715-20 he completed building Plympton House, the grand new country residence commenced by his father.
In 1725 he married Charity Hele at St. James, Westminster. She was the daughter and co-heiress of Roger Hele of Holwell, in the parish of Newton Ferrers, Devon. Her sister was Juliana Hele, wife of Peregrine Osborne, 3rd Duke of Leeds (1691–1731). By Charity he had 2 sons and 2 daughters:
In 1873 Miss Blanche Treby of Goodamoor House in the parish of Plympton St Mary was one of the major landowners in that parish and was also lord of the manor of Plympton St Maurice, in which is situated Plympton House.