Siri Tachi was a female member of the Jedi Order during the final decades of the Republic Era. Known to fellow Jedi Obi-Wan Kenobi, the two ate midday meal together at the Jedi Temple on the planet Coruscant at least once, and Kenobi thought about touching hands with her under the table. Due to the Jedi beliefs on non-attachment, however, Kenobi feared that the mere thought of what he wanted to do with Tachi meant he deserved punishment from the Jedi Council. Kenobi also suspected that Tachi would have been open to a physical relationship had Kenobi ever expressed a desire to pursue one with her. As a Padawan, Tachi was apprenticed to a Jedi Master who frequently took her on important missions.
In 22 BBY, the Clone Wars between the Galactic Republic and Confederacy of Independent Systems began. As the Jedi Order served the Republic, its members were thrust into service with the newly-formed Grand Army of the Republic. Tachi had a Padawan at the time. Due to the needs of the war, the Order rushed to promote multiple senior Padawans to the rank of Jedi Knight, and held a mass Knighting Ceremony at the Jedi Temple training ground a few weeks into the conflict. One of the new Knights promoted at the ceremony—who included Anakin Skywalker, D'urban Wen-Hurd, Olana Chion, Cyruss Okent, and Keer Stenwyt—was Tachi's former apprentice, and the Jedi was among the available mentors of the new Knights who attended the ceremony.
At the war's end in 19 BBY, the Jedi Order and Galactic Republic fell due to the machinations of the Sith, its ancient enemy. Kenobi was one of the few survivors of the beginning of the Great Jedi Purge, and went into exile from the new Galactic Empire for nineteen years before dying during the rescue of Princess Leia Organa from the Imperial Death Star superweapon. He subsequently became a Force spirit. Three years later, in 3 ABY, Kenobi thought about his history with Tachi while reflecting on the fact that Yoda, another exiled Jedi Master, kept the Order's dedication to posturing theatrics alive. Kenobi added that he had never questioned the Order about this whilst living in the Temple, and that he sometimes was not able to recognize what he believed in and what had been told to him over and over before he was old enough to understand its meaning.
Siri Tachi was first mentioned in the current Star Wars canon in the short story "There Is Always Another" by Mackenzi Lee, published in the 2020 anthology From a Certain Point of View, and first appeared in the 2022 novel Brotherhood, written by Mike Chen. In the Star Wars Legends continuity, Siri Tachi first appeared in Jedi Apprentice: The Captive Temple, the seventh novel in the Jedi Apprentice junior novel series, written by Jude Watson. A friend and occasional love interest of Obi-Wan Kenobi, Tachi was a Human female who eventually rose to the rank of Jedi Master. Lee was inspired to include a mention of Tachi in her short story due to being a fan of the Jedi Apprentice series.