Rukia Kuchiki (Japanese: 朽木 ルキア, Hepburn: Kuchiki Rukia) is a fictional character in the anime and manga series Bleach created by Tite Kubo. In the series, she is a Soul Reaper, (死神, Shinigami, literally 'Death God'), in charge of slaying and eradicating corrupted souls called Hollows, whose unfortunate fate lies destined for ruthless killing and feeding off of living beings. Along with eradicating Hollows, Rukia's primary objective as a Shinigami is to pass on the souls of those who have failed to pass on those who have yet to cross by means of konsō (魂葬, Soul Funeral). At the beginning, after a brief meeting with the protagonist of the series, Ichigo Kurosaki, who can see supernatural beings such as Soul Reapers, she transfers her powers to him in order to fulfill her duties as a Soul Reaper. Rukia has appeared in several other pieces of Bleach media, including the four feature films in the series, the two original video animations and several video games.

Rukia was the first character of the series created by Kubo, her design being the one he decided to use for all the other Soul Reapers. Reaction to her character is generally positive, with praise aimed at her differences from typical shōnen heroines and her interactions with other characters. Additionally, she usually ranks second in Weekly Shōnen Jump's Bleach popularity polls, and is consistently the most popular female character in those polls. Several pieces of merchandise have been released in Rukia's likeness, including a plush doll and several figurines.^{[citation needed]}

Bleach was first conceived from Tite Kubo's desire to draw a shinigami in a kimono, which formed the basis for the design of the Soul Reapers. Because of this, Rukia was one of the first characters of the series to be created. Before deciding that every Soul Reaper had swords, Kubo thought that they should all use guns, while only Rukia used a scythe. However, this was changed when he created the Soul Reaper kimono. Kubo also mentioned that Rukia did not seem like a lead character, so he created Ichigo Kurosaki to be the series protagonist, with Rukia being the first female lead. Ichigo's initial design had black hair like Rukia; Kubo had to modify Ichigo's appearance to contrast with hers, giving Ichigo orange hair and a trademark scowl.

As for her name, Kubo stated that, because Rukia "looks like a shinigami", he wanted her name to sound like something a shinigami would have as a name. When deciding upon her family name, Kubo considered using "Kuchiru" (朽ちる; lit. "to rot") because it sounded like a name a shinigami would have. He decided to use "Kuchiki" (朽木; lit. "rotten wood"), having once heard something that sounded like "Kuchiki Rukia" on Japanese television and liking it enough to use it as a name. Her first name was conceived as a result of Kubo hearing the Latin name for cosmos on television, and later decided that the name really suited her since the Latin word from which her name is derived means "light" and Kubo sees her as "a ray of light for Ichigo." Shonen Jump asked in an interview if Kubo had any plans to make Ichigo and Rukia a couple, but Kubo chose neither to confirm nor deny it. After designing Rukia's zanpakutō, Kubo noted he liked it a lot and made it the most beautiful one from the series.

When asked to design a Christmas cover with a female character, Kubo initially thought of using Rukia, but eventually chose Orihime Inoue as he thought the character was better suited for it—he has stated that he previously made a Christmas illustration with Rukia, and that he received requests from several fans wanting to see the image. In contrast to this, Kubo has found that he liked Rukia more in the illustrations where her face expresses pain, such as when she is going to be executed in the manga.

Rukia meets Ichigo in the midst of a hollow attack. After suffering severe injuries, she transfers her powers to him in order to save themselves. Without her powers, Rukia cannot return to the Soul Society. She accompanies Ichigo in the real world, intending to stay until her powers are restored. Therefore, her only ability is her kidō spells, which are severely limited in strength and variety. She uses her kidō for such purposes as restraining, healing and attacking others. Because of the amount of time she spends with Ichigo, Rukia manages to gain a keen understanding of his inner workings. Rukia's relationship with Ichigo is unique, for despite the relatively short amount of time they have known each other, Ichigo can easily confide in her and considers her a true friend because she is encouraging and understands what he is feeling. During her time in the human world, Rukia remains unaccounted for in Soul Society, so Byakuya Kuchiki and Renji Abarai are sent to find her and return her to the Soul Society. They succeed, and upon their return Rukia is sentenced to death for giving her Soul Reaper powers to a human. Ichigo goes to the Soul Society, in order to save her.

During the arc, Rukia's past is explored. She died as an infant and was sent to the Soul Society with her older sister, Hisana. Though Hisana initially tried to protect and provide for Rukia, she could not ensure her own survival while caring for a baby as well, and thus abandoned Rukia. As Rukia grew up, she befriended Renji Abarai, and entered the Soul Reaper academy, where she was adopted into the Kuchiki family. One year prior to the adoption, Hisana died after asking Byakuya to find and adopt Rukia as his sister. This remains unknown to Rukia, until Byakuya confesses it to her. When she was accepted into the 13th Division, Rukia befriended the lieutenant of her division, Kaien Shiba, and trained under him. During the course of a mission, Kaien was possessed by a hollow and Rukia inadvertently kills him.

During Rukia's bid for freedom, she is stopped by Sousuke Aizen and his accomplices. Aizen, having singlehandedly orchestrated Rukia's execution, reveals to her that within her soul is stored the Hōgyoku ("breakdown sphere"), a powerful artifact created and placed there by Kisuke Urahara that gives hollows Soul Reaper powers and vice versa. Wanting the Hōgyoku for himself, Aizen hoped that her death would give him access to it, but settles for a nonfatal alternative. The Hōgyoku is removed from her body, Aizen and his men flee Soul Society, and Rukia is acquitted of all charges. With the Hōgyoku, Aizen is able to create an army of arrancar, which he uses to attack Ichigo and his friends once they return to the human world. Rukia and a group of other Soul Reapers are sent to assist in fighting the arrancar, though after Aizen captures Orihime Inoue they are recalled to Soul Society. Rukia's zanpakutō, Sode no Shirayuki (袖白雪; literally "Sleeved white snow"), is also revealed as a completely white blade, earning it the recognition as the most beautiful zanpakutō in Soul Society. Sode no Shirayuki utilizes ice to attack, each of its abilities being labeled as "dances" by Rukia. During the anime's 13th season, Sode no Shirayuki manifests in a yukionna-like form, voiced by Mie Sonozaki.