Tonil Hornung was a female human Starfleet officer in the 24th century. In May 2381, Lieutenant Hornung served aboard the Vesta-class USS Quirinal as chief science officer when it was assigned to Project Full Circle. In September of the same year, Hornung accompanied Captain Regina Farkas to a meeting aboard the USS Esquiline to discuss the effects of the Omega Continuum fractures into normal space. Farkas offered points to anyone who could explain it to her so that she understood, and pointed out that Hornung had not earned any points so far, to which Hornung grimaced.