B'Elanna is half-human and half-klingon. Her mother was Klingon and tried to teach her the ways of the Klingon, but B'Elanna rebelled against many of the Klingon beliefs. Her father, a human Starfleet officer, left her mother when B'Elanna was five, and her and her mother moved to Kronos, the Klingon Homeworld. She is intelligent, and has strong engineering skills. She has a hard time controlling her temper and can be very aggressive, which is why she dropped out of Starfleet Academy after her second year. She then joined the Maquis and served as Chakotay's engineer. When the Maquis ship was destroyed by the Caretaker, she became the Chief Engineer aboard the U.S.S. Voyager, with a field promotion to Lieutenant.

Starfleet History
2359-2361 Attended Starfleet Academy. Dropped out in second year. Academy Professor P. Chapman recommended B'Elanna for re-admission.
2370 Joined Maquis resistance.
2370 Chief Engineer aboard Maquis raider commanded by Chakotay.
2371 When the Maquis ship was destroyed after being pulled into the Delta Quadrant, the crew was transferred to U.S.S. Voyager.
2371 Chief Engineer U.S.S. Voyager NCC-74656. Field promotion to Lt. j.g.
2374 Arrested on Mari homeworld for thinking violent thoughts.
2374 Adapted Voyager's EMH program for transmission over alien comm array to the Federation starship U.S.S. Prometheus in the Alpha Quadrant.
2374 Assisted with design and construction of The Delta Flyer.

B'Elanna Torres was first seen in "Caretaker" (VOY).