In Final Fantasy X, Yuna is introduced as a summoner who can use healing magic and is able to summon powerful magical entities called aeons with help from spirits known as Fayths. Already known throughout Spira as the daughter of High Summoner Braska, who previously brought a brief respite from Sin's destruction ten years earlier, Yuna decides to embark on the summoner's pilgrimage to become a High Summoner herself. Yuna must journey to temples across the world, acquire the aeon from each and summon the Final Aeon in a battle that will kill them both. She gradually becomes more open and falls in love with Tidus. Upon arriving at the place where Yuna can summon the final aeon, Tidus persuades the group to look for another way to defeat Sin without using any sacrifices. After entering Sin's body, Yuna and her guardians defeat the disembodied spirit of Yu Yevon, who is responsible for reviving Sin after each defeat, allowing an eternal Calm to start in Spira. However, Tidus disappears as he is the product of the Fayth, who could not depart until Sin's defeat.
In Final Fantasy X-2, set two years after Final Fantasy X, Yuna is a member of the sphere hunting group Gullwings, along with Rikku and Paine. In the game's
international version, the Gullwings go their separate ways before the game's opening, with Yuna returning to Besaid Island. The trio then reunite to explore a tower. In X-2, Yuna journeys to Spira in search of the truth behind a sphere containing a video featuring a man resembling Tidus in prison. During her journey, Yuna discovers the man from the sphere was actually Shuyin, a spirit who wishes to destroy Spira in revenge for the death of his lover, Lenne. The Gullwings defeat Shuyin who departs to the afterlife with Lenne's spirit. Depending on the player's progress throughout the game, the Fayth may revive Tidus so that she can reunite with him. The HD Remastered version of the game adds a new audio drama where Yuna becomes a part of the group called Yevoners whose main temple is located on Besaid. In the story she breaks up with Tidus after telling him she loves somebody else before declaring she will fight Sin once again.
She also appears in Dissidia 012 Final Fantasy, an action game that features several Final Fantasy characters, as one of the characters to be summoned by the goddess Cosmos to participate in a war against her rival Chaos. For this game, Yuna appears in her Final Fantasy X form but sightly arranged to fit with the game's cast. Additionally, she has an alternative design based on Yoshitaka Amano's illustration, and a wedding dress from Final Fantasy X. Her Final Fantasy X-2 regular form was made available as downloadable content.
Outside the Final Fantasy series, Yuna appears in Kingdom Hearts II as a pixie along with Paine and Rikku. Bribed by Maleficent into spying on Leon's group, the pixies eventually switch sides after being abandoned by the witch and told of Sora's cause. Yuna is also featured in the board game style video game Itadaki Street Special, appearing alongside Auron and Tidus, and represents Final Fantasy X in the rhythm game Theatrhythm Final Fantasy.
Multiple figures and figurines of Yuna were produced by various manufacturers, including a 2001 figure by Square. A 2003 audio CD Final Fantasy X-2 Vocal Collections features performances by Mayuko Aoki, Marika Matsumoto and Megumi Toyoguchi, the voice actresses for Yuna, Rikku and Paine, respectively.