USS Sibyl was a wooden-hull steamer outfitted with heavy guns, purchased by the Union Navy during the American Civil War.

Sibyl was used by the Union Navy primarily as a dispatch boat in the blockade of ports and waterways of the Confederate States of America.

Sibyl was based at Cairo, Illinois, and used as a dispatch boat for Rear Admiral David Dixon Porter, the commander of the Mississippi Squadron.

Her first cruise began early in July and took her downriver as far as Natchez, Mississippi, delivering messages to Navy ships en route.

She continued this type of service through the end of the Civil War, gathering intelligence of Confederate activity as she steamed up and down the river.