Deanna Troi is a fictional character from the television series Star Trek: The Next Generation. She serves as the ship's counselor aboard the USS Enterprise-D, where she uses her empathic abilities to understand and help the crew with their emotional and psychological challenges. Troi is half-human and half-Betazoid, which allows her to sense the feelings of others, making her an essential part of the team. Portrayed by actress Marina Sirtis, Troi is known for her distinctive Starfleet uniform, which includes a form-fitting dress. Throughout the series, she develops close relationships with other crew members, particularly with Captain Jean-Luc Picard and Commander William Riker, her former romantic partner.