Ukranian in descent, Yar was born on a failed Federation colony on Turkana IV. Her parents were killed when she was five. She spent the next 10 years struggling for survival, evading rape gangs and caring for her younger sister, Ishara Yar. Tasha escaped Turkana IV when she was fifteen and joined Starfleet. Her sister stayed behind and joined the Coalition.

In late 2364, Tasha was killed in the line of duty by an entity named Armus while participating in a rescue mission on Vagra II. She left a holographic farewell message to her crewmates.

Starfleet History
2352-2356 Attended Starfleet Academy.
2359 Posted to U.S.S. Bellerophon NCC-62048. Security officer.
2363 Citation for Bravery, rescue mission on planet Carnel.
2364 Promoted to Lieutenant.
2364 Posted to U.S.S. Enterprise NCC-1701-D, Chief of Security
2364 Killed in the line of duty on Vagra II by Armus.
2367 Romulan Commander Sela claimed to be the child of Tasha Yar and the Romulan general who captured the crew of the U.S.S. Enterprise NCC-1701-C in 2344. According to Sela, a temporal rift caused the Enterprise-C to jump into the future and Yar remained on board the Enterprise-C when the ship returned to its proper time period.

Natasha Yar was first seen in "Encounter at Farpoint" (TNG).