The Kil'j Tholis was a Tholian starship in service to the Tholian Assembly in the mid-23rd century.
In 2265, the Kil'j Tholis was one of six Tholian ships that attacked the USS Bombay in orbit of Ravanar IV. It was destroyed along with the Tas'v Tholis when the Starfleet vessel engineered a collision between the two with its tractor beam. (VAN novel: Harbinger)