The Theophrastus-class was a type of Federation starship in service during the late-24th century.
The Theophrastus-class was a small, sleek vessel, capable of being outfitted with quantum slipstream drive.
In May of the year 2381, one Theophrastus-class vessel, the USS Demeter, was assigned to Project Full Circle to explore the Delta Quadrant. (VOY novel: Children of the Storm)
Lieutenant Garvin Elkins, chief engineer of Demeter, was one of the designers of the Theophrastus class. (VOY novel: A Pocket Full of Lies)
The Theophrastus class was smaller than the Galen-class, another single-purpose experimental starship type. In August 2382, Demeter was the smallest starship in the Full Circle fleet. (VOY novel: Architects of Infinity)