Erastus Root (March 16, 1773 in Hebron, then Windham County, now Tolland County, Connecticut – December 24, 1846 in New York City) was an American lawyer and politician from New York.
Root graduated from Dartmouth College in 1793 and became a teacher. Then he studied law, was admitted to the bar in 1796, and commenced practice in Delhi, New York.
Erastus Root was a member of the New York State Assembly (Delaware Co.) in 1798–99, 1800–01 and 1802. Root was elected as a Democratic-Republican to the 8th United States Congress, holding office from March 4, 1803, to March 3, 1805. Afterwards he resumed his law practice. He was then elected to the 11th United States Congress, holding office from March 4, 1809, to March 3, 1811, and was Chairman of the Committee on Claims. Root was a member of the New York State Senate (Middle D.) from 1812 to 1815, sitting in the 35th, 36th, 37th and 38th New York State Legislatures.