USS Proteus was a steamer armed with powerful ordnance, commissioned by the Union Navy during the American Civil War.

Proteus served during the blockade of ports and waterways of the Confederate States of America as a gunboat, patrolling primarily the waters off the coast of Florida.

On 14 May she got underway for Cuba, where she watched for blockade runners bound for Wilmington, North Carolina from the Windwards.

Arriving there on 12 July 1865, after the war's end, she was sold at public auction to the firm of Hooper and Co. and entered commercial service under the name Carroll.

After a short and unsuccessful transatlantic career, Carroll was sold again and placed in service between Boston, Massachusetts, and Canada.