A high adviser was a diplomatic title held by the leader of Ardana's planetary council.

The high adviser was given several rights and responsibilities on Ardana, ranging from conducting welcoming ceremonies for off-world visitors, to issuing planet-wide policies – up to possessing the authority to have lawbreakers, even lawbreaking Starfleet officers, executed.

In 2269, the position of high adviser was held by Plasus. (TOS: "The Cloud Minders")