Gilnor was a Mordanite, who contested with Karnas for power in 2319. Sometime before 2364, Gilnor died.

In an investigation into who might have kidnapped Ambassador Hawkins and his staff in 2364, Admiral Mark Jameson suggested this name in his conversation with Karnas. Karnas informed the admiral that his old rival was dead. With Gilnor and Ardan both deceased, Jameson suspected Karnas as the perpetrator of the criminal act. (TNG: "Too Short a Season")

This character was only mentioned in dialogue.