What is the name of the ship's counselor on the Enterprise-D?

The ship's counselor on the Enterprise-D is Deanna Troi. She serves as the crew's counselor aboard the USS Enterprise-D, advising officers, supporting civilians, and using her empathic abilities to interpret the emotions of people encountered by the ship.

Troi is half-Betazoid and half-human, and her Betazoid heritage gives her the ability to sense emotions. She is portrayed as a trained professional rather than merely a telepathic plot device: her background includes psychology studies at the University of Betazed and Starfleet Academy. Her role often places her between medical care, diplomacy, conflict resolution, and command decision-making.

A frequent mix-up involves Lwaxana Troi, Deanna's Betazoid mother, who is a flamboyant diplomat and recurring visitor rather than the Enterprise-D counselor. Dr. Beverly Crusher is the ship's chief medical officer, while Guinan is the bartender and a trusted adviser in Ten Forward. Troi later passes the bridge officer's examination, is promoted to commander, and continues serving as counselor.