David Legge Brainard (December 21, 1856 – March 22, 1946) was a career officer in the United States Army. He enlisted in 1876, received his officer's commission in 1886, and served until 1919. Brainard attained the rank of brigadier general and served during World War I as U.S. military attaché in Lisbon, Portugal.

A native of Norway, New York, Brainard was raised and educated in Norway and nearby Freetown, and graduated from the State Normal School in Cortland, New York.

In addition to his First World War service, Brainard was a veteran of the American Indian Wars, Spanish–American War, and Philippine–American War. He was also a noted arctic explorer who attained fame as one of only six survivors of the 1881 to 1884 Lady Franklin Bay Expedition. He was the recipient of several civilian awards in recognition of his explorations. He died in Washington, D.C., on March 22, 1946, and was buried at Arlington National Cemetery.

Brainard was born in Norway, New York on December 21, 1856, the fifth son of Alanson Brainard and Maria C. Legge. His family moved to a farm in Freetown, New York, when he was ten years old, and Brainard was raised and educated in Norway and Freetown. He attended the State Normal School in Cortland, New York, and then decided upon a military career.

Brainard enlisted in the United States Army in September 1876. He was assigned to the 2nd Cavalry Regiment and served at Fort Keogh, Montana Territory during the Great Sioux War of 1876. On May 7, 1877, Brainard fought in the Battle of Little Muddy Creek, Montana, where he was wounded in the face and right hand. In August 1877, Brainard was one of four soldiers assigned to escort the Army's commanding general, William Tecumseh Sherman and Sherman's party on an inspection tour of Yellowstone National Park. In 1877 and 1878, he served under Nelson Appleton Miles in Montana during the Nez Perce War and Bannock War. He was promoted to corporal in October 1877, and sergeant in July 1879.

In 1880, Brainard was selected for the Howgate expedition, which started for Greenland in July 1880, but turned back after a heavy storm damaged the expedition's ship. In 1881, he was detailed as first sergeant for the Lady Franklin Bay Expedition, which was commanded by Adolphus Greely. Over the three years of this expedition he continuously kept a journal.

Twenty-five men began the expedition, which ran into difficulty when several attempts to resupply it failed, and several rescue attempts were forced to turn back. Among those who died was James Booth Lockwood, second-in-command and Brainard's companion on many excursions, including their record breaking push north to latitude 83° 23' 30". Brainard wrote:

Lieut. Lockwood became unconscious early this morning and at 4:30 pm breathed his last. This will be a sad blow to his family who evidently idolized him. To me it is also a sorrowful event. He had been my companion during long and eventful excursions, and my feeling toward him was akin to that of a brother. Biederbick and myself straightened his limbs and prepared his remains for burial. This was the saddest duty I have ever yet been called upon to perform.