Augustus Brandegee (July 12, 1828 – November 10, 1904) was an American lawyer and politician who served in the United States House of Representatives from Connecticut.

His father was from a Connecticut family, and relocated to New Orleans cotton broker; he later returned to New London and became active in the whaling industry and other business ventures.

In 1845 Brandegee entered Yale University, where he was elected membership to Delta Kappa Epsilon and Skull and Bones.

He was also chairman of the select committee to manage the "bill for the defense of liberty," which was aimed at preventing the enforcement of the Fugitive Slave Law in Connecticut.

Later, Brandegee chaired the committee which oversaw passage of Connecticut's version of the Maine liquor law, which prohibited the sale of alcoholic beverages.

In 1860, he was chosen as one of Connecticut's electoral college members, on the Republican ticket headed by former Governor Roger Sherman Baldwin; Abraham Lincoln carried Connecticut, and the electors cast their ballots for Lincoln for president and Hannibal Hamlin for vice president.

At the end of the year, fellow Bonesman and the leader of the Democrats in the House, Henry C. Deming presented him with a silver service as a token of appreciation for his impartiality.

Respected as an ardent abolitionist as well as a friend of President Abraham Lincoln, he and a fellow Representative, Democrat James E. English of New Haven voted in favor of the momentous 13th Amendment in 1864 that outlawed slavery; Steven Spielberg's 2012 film Lincoln erroneously depicts them as two Connecticut Democrats with fictional names voting against the amendment.

After his service as Mayor his fellow Republicans had tried to convince him to run for Governor or Senator, but Brandegee declined any further elected offices, although he served as Corporation Counsel of New London in 1897 and 1898.

In manner unexcelled he clothed his thoughts in language chaste and beautiful, and drove his words deep into the hearts of his hearers.

He fought them all his days and when the end came, passed over God's threshold with escutcheon unstained and with plume untarnished.Brandegee was the husband of Nancy Christine Bosworth (1840–1881).