Aaron Simon Daggett (June 14, 1837 – May 14, 1938) was a career United States Army officer.

[2][3] Daggett was nominated for appointment to the grade of brevet brigadier general, to rank from March 13, 1865, by President Andrew Johnson on February 21, 1866, and was confirmed by the United States Senate on April 10, 1866.

[2] He was appointed to the brigadier general grade to rank from September 1, 1898, and was mustered out of the volunteers on November 30, 1898.

[2] He fought at Second Fredericksburg, Gettysburg, Mine Run, the Wilderness, and Cold Harbor where he was wounded on May 30, 1864.

[2] On January 23, 1865, he was appointed lieutenant colonel of the 5th United States Veteran Volunteer Infantry Regiment.

[4] Daggett believed in the abolition of slavery and fought alongside African-American soldiers during the Civil War while serving with the 5th Maine Infantry Regiment.

During the Spanish–American War, Daggett was temporarily appointed to the brigadier general grade to rank from September 1, 1898, and was mustered out of the volunteers on November 30, 1898.

[2][6] Aaron S. Daggett died at the age of 100 at his home in West Roxbury, Massachusetts, on May 14, 1938, making him the last surviving brevet or full, substantive rank Union general of the Civil War.