Thomas Burnside (July 28, 1782 – March 25, 1851) was an American politician and judge who served as a Democratic-Republican member of the United States House of Representatives for Pennsylvania's 9th congressional district from 1815 to 1816 and as an associate justice of the Supreme Court of Pennsylvania from 1845 until his death in 1851.

Thomas Burnside was born near Newtownstewart, County Tyrone, Ireland. He emigrated to the United States with his father’s family, who settled in Norristown, Pennsylvania, in 1793. He studied law, was admitted to the bar in 1804 and commenced practice in Bellefonte, Pennsylvania.

He was appointed deputy attorney general on January 12, 1809, and served in the Pennsylvania State Senate for the 13th district from 1811 to 1814 and again from 1823 to 1826 when he also served as Speaker of the Senate.

Burnside was elected as a Democratic-Republican to the Fourteenth Congress to fill the vacancy caused by the death of David Bard and served until his resignation in April 1816. He was appointed president judge of the Luzerne district courts in 1815, and resigned in 1819. He was again a member of the Pennsylvania State Senate and its presiding officer in 1823. He was president judge of the fourth judicial district from 1826 to 1841 and later presided in the same capacity over the seventh judicial district. He was appointed an associate justice of the Supreme Court of Pennsylvania in 1845, which office he held until his death in Germantown, Pennsylvania.