Lieutenant Natasha Yar, better known as Tasha, was a Human Starfleet officer born on Turkana IV, and former security chief on the USS Enterprise-D. Unfortunately, Tasha was killed not even a year into the Enterprise's mission. She was fondly remembered by the Enterprise crew, and an alternate timeline version of Tasha indirectly played a very important role in Romulan politics.

Tasha was born in 2337 on the failed colony world of Turkana IV. Her sister, Ishara, was born five years later. Both of their parents were killed shortly following Ishara's birth, leaving Tasha to care for them both. Tasha had to avoid rape gangs and terrible violence just to scavenge for the bare necessities of life, such as food. One of the only bright spots in her life was finding a cat, which she attempted to protect while being chased by a rape gang. Drug use was also commonplace. Tasha apparently resorted to drugs as an escape at some point, but later remembered that they were of more harm to her than good.

Although Ishara decided to remain on the planet and eventually joined the Coalition, Tasha managed to find a way off Turkana IV in 2352 by the age of fifteen. Ishara and Tasha never saw one another again. Tasha began to attend Starfleet Academy soon after her escape. Tasha credited Starfleet for saving her from her previous life. She joined security because of the lawless environment in which she grew up.

In 2363, while conducting a rescue mission, Yar rescued a colonist after traversing a Carnelian minefield. Captain Jean-Luc Picard's ship at the time was also present. Picard was so impressed with her bravery that he recruited Yar for duty on the Enterprise at that time, as Yar's then commanding officer owed him a favor.

Yar was an expert in aikido, a form of martial arts, and regularly used several holodeck training programs. She was also a parrises squares player. Three days before her death, Yar was scheduled to participate in a martial arts competition with science officer Swenson and Lieutenant Minnerly. She was favored to win in the ship's pool.