USS Seneca (AT-91) was a Navajo-class fleet tug constructed for the United States Navy during World War II.

From 27 June until 7 July, she conducted anti-submarine warfare (ASW) training in the Guantanamo Bay operating area; then she headed for Trinidad to begin a tour of duty with the U.S. 4th Fleet.

For the next 21 months, Seneca was assigned target towing, general rescue, and salvage duties in the waters off the coast of Brazil.

During one of her early rescue missions, Seneca captured two survivors of a German U-boat sunk by Allied ASW patrols.

She spent much of her career in the Guantanamo Bay area and in the British West Indies, but also frequented the New England, Canadian, and Greenland coasts.

Three of her more important evolutions before decommissioning were the tows of the Aircraft Carriers Essex and Randolph from the Boston Army Piers in Boston to the Brooklyn Navy Yard and tows of WW II Vessels from the Hudson River Reserve Fleet in the ongoing effort to clean up the Hudson encouraged by President Nixon. Decommissioned in July 1971, Seneca was transferred to the Maritime Administration on 18 November 1971 for lay up with the James River Group, National Defense Reserve Fleet, Fort Eustis, Virginia.

The ship was moored at the former Engineering Experiment Station[1] in Annapolis, Maryland, later part of the Carderock Division of the Naval Surface Warfare Center.