The USS Zife was a Federation starship in service to Starfleet in the early 25th century.

In 2409, the ship found Charles Ryerson in a craft traveling at relativistic speeds near Barnard's Star. Ryerson was experiencing the time dilation effect, due to the speed his ship was coasting at. As a result, he experienced only a short amount of time since his departure, while to the rest of the universe, 20 years had passed. (STO novel: The Needs of the Many)