USS Penobscot was a Unadilla-class gunboat built for the Union Navy during the American Civil War.

On 1 August she seized sloop Lizzie off New Inlet and on 22 October British brig Robert Burns off Cape Fear.

Continuing her patrol of the Carolina coast into the summer of 1863, she forced blockade runner Kate ashore at Smith's Island 12 July.

On 12 July, off Galveston, Texas, the "ninety-day" gunboat intercepted the schooner James Williams with a cargo of medicine, coffee, and liquor.

She forced the schooners Mary Agnes and Louisa ashore at Aransas Pass and on the 19th sent a boat crew to destroy them.