The USS Marignano was a Federation starship, a long-range pure science vessel commanded by Captain Ileen Maisel. The Marignano's was half the size of a Galaxy-class starship with a narrower saucer and overly large engineering section and nacelles. The Marignano had a crew of approximately 470 and two cargo bays.

In 2369, the Marignano began a long-term exploration program on the Great Rift that continued for at least two years. The Marignano also did a large amount of escort work in nearby sectors. The ship assisted the USS Enterprise-D in destroying the intellivore in 2371; 115 crewmembers died in the attempt. (TNG novel: Intellivore)