USS Flag was a screw steamship in the Union Navy during the American Civil War.

Aside from periods in the North for repairs, she patrolled the coastal waters of the Carolinas until early 1865.

[1] On 24 November, she joined Seneca and Pocahontas in taking possession of Tybee Island, evacuated previously by the Confederates, and two days later drove several southern ships back into Fort Pulaski, from which they were attempting to sail.

She participated in the capture of Fernandina, Florida in March 1862, and in the general engagement of the fleet with the forts in Charleston Harbor on 7 April 1863.

This article about a specific ship related to the American Civil War is a stub.