George Treby of Plympton House, Plympton St Maurice, Devon, was an English Whig politician who sat in the House of Commons for 34 years from 1708 to 1742. He was Secretary at War from 1718 to 1724, and Master of the Household from 1730 to 1741. He built Plympton House between 1715 and 1720, which his father began and left unfinished at his death in 1700.

The Secretary at War was a political position in the English and later British government, with some responsibility over the administration and organization of the Army, but not over military policy. The Secretary at War ran the War Office. After 1794 it was occasionally a Cabinet-level position, although it was considered of subordinate rank to the Secretaries of State. The position was combined with that of Secretary of State for War in 1854 and abolished in 1863.