Star Trek Canon Special Note
Not everything listed in the origin is Canon. That is because only television shows and movies are considered canon for Star Trek. This being a comic website there are many things here that are not canon. So unless it is contradicted in film it should be listed as part of the character biography.
Daughter of Lwaxana Troi a Betazoid and Ian Andrew Troi a human. Making Deanna half Betazoid and half Human. Because of this, she is empathic rather than telepathic and has a harder time blocking out external emotions then her peers on Betazed. Deanna also had a sister Kestra Troi who drowned when Deanna was just an infant.
When she became old enough, she enrolled in Starfleet Academy to get away from her mother because while she loves her dearly, Lwaxana is overbearing and very overprotective. When Ambassador Troi learned of it, she forbade her from going and as a compromise, Deanna enrolled in the Command track even though she didn’t know what field she wished to study. It was only at the end of her first year that she decided to become a Ship’s Counselor and changed programs with her mother’s blessing.
Sometime after she graduated, she met Ensign William Riker who was stationed on Betazed. The two began a relationship that lasted several years with the usual ups and downs. Unfortunately, for her Riker’s priorities lay in his advancing his career. Plans to vacation on Risa were usurped by his promotion to Lieutenant on the U.S.S. Potemkin and they lost contact.
The character of Deanna Troi was created by Gene Roddenberry for the television show Star Trek: The Next Generation. The actress Marina Sirtis originally tried out for the part of Natasha Yar. The reason for this was Roddenberry wanted a female security officer like the character of Jenete Vasquez played by Jenette Goldstein in the film Aliens. Ironically Denise Crosby who played the Yar character was going to play the Deanna Troi character. Just before filming the actors roles were switched.
When Sirtis was going to play Troi she was told to give her character an accent because she was an alien but when Majel Barrett Roddenberry played the role of her mother she didn't have an accent. When Sirtis asked about this she was told that the accent came form her father's side. So, it is unsure what kind of accent she has.
In 2364 Counselor Deanna Troi was assigned to the USS Enterprise-D under Captain Picard and (much to her surprise) Commander Riker. She and Riker had a long romance but the decided to stay professional on the ship as they worked together. This created some awkward situations for example when she was impregnated by an alien creature and had a son who died within a few days even though he grew about eight years in that time. She also had a romance with Worf for a while but for unknown reasons it never worked out.
Deanna served aboard the flagship until its destruction in 2371 and was among most of the crew which transferred to the Sovereign-class Enterprise E. Her and Riker served on the ship together and rebuilt their romance. It took a long time but eventually Troi and Riker did get married and she joined him as he went on his new command as Captain.
Myriad Universes - The Last Generation
In this reality, Deanna is the consort to Lord Worf and giving information to Picard’s resistance. However, he is aware if it and when the movement decided to go after him he has no more use of her. When he tells Deanna this, rather than flee or beg for his forgiveness, she calls him a fool. He kisses her to silence her and stabs her in the stomach, killing her.