Viola was an officer who served in Starfleet in the mid-23rd century.

In the 2250s, Viola was assigned to the Federation starship USS Enterprise as a bridge science officer, under the command of Captain Christopher Pike. In 2254 she stood in for Spock. (TOS novel: The Rift)

USS Enterprise (NCC-1701) sciences personnel
under Charles Rasmussen & Robert April	Allinsky • Griggs • Osterman • Ramirez
under Christopher Pike	Cayman • Davies • Spock • T'Pris • Viola • Yu
under James T. Kirk (first five-year mission)	Ackroyd • Alden • Amstel • Aristeides • Avitts • Berkeley • Boma • Berry • Brent • Calloway • Charvat • D'Amato • Darnell • Erickson • Errgang • Follett • Freeman • Harrison • Irizarry • Gilden • Jaeger • Jaramillo • Lowrey • Mason • McGivers • Mendoza • Nelson • O'Shea • Owens • Phillips • Romaine • Spock • Sulu • Sydney • Tamboline • Watley • Weinberg
subsequent missions under Kirk & Spock	Bolek • Haley • Nakashima • Saavik • Spock • Tenaida • Whitehorse
see also: administrative personnel • communications personnel • engineering personnel • medical personnel • pilots & flight control personnel • security & tactical personnel • senior staff • unnamed