Hercules is a 1907-built steam tugboat that is now preserved at the San Francisco Maritime National Historical Park in San Francisco, California.

The San Francisco Maritime National Historical Park is located in San Francisco, California, United States. The park includes a fleet of historic vessels, a visitor center, a maritime museum, and a library/research facility. Formerly referred to as the San Francisco Maritime Museum, the collections were acquired by the National Park Service in 1978. The San Francisco Maritime National Historical Park was authorized in 1988; the maritime museum is among the park's many cultural resources. The park also incorporates the Aquatic Park Historic District, bounded by Van Ness Avenue, Polk Street, and Hyde Street.