| Deanna Troi | |
|---|---|
| Star Trek character | |
 Marina Sirtis as Deanna Troi | |
| First appearance |
|
| Created by | Gene Roddenberry D. C. Fontana |
| Portrayed by | Marina Sirtis |
| In-universe information | |
| Species | Betazoid (maternal) Human (paternal) |
| Affiliation | United Federation of Planets Starfleet |
| Family | Ian Andrew Troi (father, deceased) Lwaxana Troi (mother) Kestra Troi (sister, deceased) Unnamed half-brother |
| Spouse | William Riker |
| Children | Ian Andrew Troi, II (deceased) Thaddeus Troi-Riker (deceased) Kestra Troi-Riker |
| Posting | USS Titan (NEM, LDS) USS Enterprise-E (FCT, INS, VOY, NEM) USS Enterprise-D (Seasons 1–7, GEN) |
| Position | Diplomatic Officer (USS Titan) Counsellor (USS Enterprise-E, USS Enterprise-D) |
| Rank | Commander (Season 7, films) Lieutenant Commander (Seasons 1–7) |
Deanna Troi is a main character in the science-fiction television series Star Trek: The Next Generation and related TV series and films, portrayed by English actress Marina Sirtis. Troi is half-human, half-Betazoid, and has the psionic ability to sense emotions. She serves as the ship's counsellor on USS Enterprise-D. Throughout most of the series, she holds the rank of lieutenant commander. In the seventh season, Troi takes the bridge officer's examination and is promoted to the rank of commander, but continues as counsellor.
Troi appears in all four Next Generation theatrical films, and also made guest appearances on Voyager, Enterprise, Picard and Lower Decks.
Her romantic interests, family and personal life are plot elements in many Star Trek: The Next Generation episodes.