Augustus William Magee (also McGee; 1789 – 6 February 1813) was an U.S. Army lieutenant and filibuster who led an invasion of Spanish Texas in 1812.
Augustus Magee was born in Boston, Massachusetts. In 1809, he graduated third in his class at West Point. He served as an artillery officer under Major General James Wilkinson at Baton Rouge, Louisiana, and then at Fort Jesup under future president Zachary Taylor. He was effective but harsh in his treatment of settlers and outlaws, in the disputed Neutral Ground between the Arroyo Hondo and the Sabine River. He was recommended for, but refused, promotion to a higher rank.
Frustrated with his prospects, he considered Bernardo Gutiérrez de Lara's plan to support the Mexican War of Independence via an invasion of Texas from American soil. Although this proposal defied the Neutrality Act, Magee resigned his commission in June 1812 and personally recruited many of the soldiers.
Leaving with 130 men on 2 August 1812, now-Colonel Magee crossed the Sabine six days later. On August 10, he was joined by General Gutiérrez; on the 16th, the Gutiérrez–Magee Expedition entered Nacogdoches. The force (now swollen to about 300) occupied Santísima Trinidad de Salcedo (now Trinidad, Texas) on the Trinity River, in mid-September. Here, Magee became ill. Some sources attribute this to consumption or malaria, but the papers of Mirabeau Lamar preserve the Texan rumor that Magee was poisoned by his men, many of whom were among those he had previously mistreated during his former command.