Thomas Wallace, 1st Baron Wallace PC (1768 – 23 February 1844) was an English politician.
Wallace was the son of James Wallace (1729–1783), a barrister who served as Solicitor General for England and Wales and as Attorney General, by Elizabeth, only daughter and sole heiress of Thomas Simpson, Esquire, of Carleton Hall, Cumberland.
Wallace was Member of Parliament for Grampound from 1790 to 1796, for Penryn from 1796 to 1802, for Hindon from 1802 to 1807, for Shaftesbury from 1807 to 1812, for Weymouth from 1812 to 1813, for Cockermouth from 1813 to 1818 and again for Weymouth from 1818 to 1828. He was a member of the Board of Control from 1807-1816 (responsible for overseeing the British East India Company), and Vice-President of the Board of Trade from 1818 to 1823. He was appointed a Privy Counsellor in 1801 and ennobled as Baron Wallace, of Knaresdale in the County of Northumberland, on 2 February 1828.
Lord Wallace married Lady Jane, daughter of John Hope, 2nd Earl of Hopetoun, in 1814. His seat was at Featherstone Castle, Northumberland. Lady Jane died in June 1829. Lord Wallace survived her by 15 years and died in February 1844. The barony died with him.