General Sylvanus Thayer (June 9, 1785 - September 7 1872) was an early superintendent of the United States Military Academy at West Point and an early advocate of engineering education in the United States.

Thayer was born in Braintree, Massachusetts, the son of farmer Nathaniel Thayer and his wife Dorcas. In 1799 at the age of 14, Thayer was sent to live with his uncle Azariah Faxon and attend school in Washington, New Hampshire. There he met General Benjamin Pierce, who, like Faxon, was a veteran of the Revolutionary War. In 1803 Thayer matriculated at Dartmouth College, graduating in 1807 as valedictorian of his class.

Thayer, however, never gave the valedictory address at Dartmouth, having been granted an appointment to West Point by President James Madison at the behest of General Pierce. Thayer graduated from the Military Academy in a single year, and received his commission as a second lieutenant in 1808.

During the War of 1812, Thayer directed the fortification and defense of Norfolk, Virginia and was promoted to major. In 1815, Thayer was provided $5,000 to travel to Europe, where he studied for two years at the French École Polytechnique. In 1817, President James Monroe ordered Thayer to West Point to become superintendent of the Military Academy. Under his stewardship, the Academy became the nation's first college of engineering.

Colonel Thayer's time at West Point ended with his resignation in 1833, after a disagreement with President Andrew Jackson. Thayer returned to active duty in the Army Corps of Engineers. He retired in 1863 with the rank of brigadier general.

In 1867, Thayer donated $30,000 to the trustees of Dartmouth College to create the Thayer School of Engineering. Thayer personally located and recommended USMA graduate Lieutenant Robert Fletcher to Dartmouth president Asa Smith. Fletcher became the school's first--then only--professor and dean.

The Thayer School admitted its first three students to a graduate program in 1871. Sylvanus Thayer died on September 7, 1872 at his home in Braintree. He was reinterred at West Point in 1877.