USS Mackinaw was a 974-ton sidewheel gunboat of the United States Navy which saw service during the American Civil War.

She destroyed the steamer Georgiana McCaw 5 June and supported Union troops on their advance from Dutch Gap, Va., 11 August.

Transferred to the Wilmington blockade, Mackinaw chased a steamer 7 November and captured schooner Mary east of Charleston 3 December.

She went into action against Fort Anderson 18 February, shelling the works at Port Royal until the latter part of April.

Recommissioned 18 January 1866, Mackinaw served in the North Atlantic Squadron and in the West Indies until decommissioning 4 May 1867.