Outlaw Star (星方武侠アウトロースター, Seihō Bukyō Autorō Sutā; lit. "Starward Warrior Knight Outlaw Star") is a Japanese media mix primarily consisting of an anime television series produced by Sunrise (now a division of Bandai Namco Filmworks) and a corresponding seinen manga series written and illustrated by Takehiko Itō. The series takes place in the "Toward Stars Era" universe in which spacecraft are capable of traveling faster than the speed of light. The plot follows protagonist Gene Starwind and his motley crew of an inherited ship dubbed the Outlaw Star, as they search for a legendary outer space treasure trove called the "Galactic Leyline".

Planned by Sunrise (under the Hajime Yatate pseudonym) and Itō, Outlaw Star first appeared as a manga originally serialized in the monthly Shueisha magazine Ultra Jump between 1996 and 1999 for a total of 21 chapters. Three volumes of collected chapters were published in Japan between August 1997 and January 1999. Although no official English version of the manga exists, it has been published in Chinese, German, Italian, and Spanish. Sunrise produced a 26-episode anime adaptation that was directed by Mitsuru Hongo and aired on the Japanese station TV Tokyo in early 1998. The animated series has since been translated and broadcast worldwide. This includes an English version from Bandai Entertainment that received an edited airing on the North American Cartoon Network blocks Toonami in early 2001 and later on Adult Swim in early 2002. Outlaw Star has been licensed for release in Australia and New Zealand by Madman Entertainment and in Europe by Beez Entertainment. A few Japanese-exclusive audio CDs and light novels have been spawned since the start of the manga's publication.

Critical reception for Outlaw Star has been mostly positive. Many reviewers praised the anime series, particularly its animation style and its balance of dramatic and comedic elements. However, some found fault with the show's pacing, believing that the storyline quality begins to wane after the first few episodes. Sunrise produced a spin-off television series titled Angel Links (星方天使エンジェルリンクス, Seihō Tenshi Enjeru Rinkusu; lit. "Starward Angels Angel Links"), which aired in Japan in 1999. Preliminary plans were made to create a direct sequel in the form of a single-episode (OVA) called Sword of Wind, but production never began.

Outlaw Star is a space opera/space Western set in the fictional "Towards Stars Era" (到星歴, Tōseireki) universe. During its past, an asteroid containing a material known as "dragonite" crashed in the fictional Arashon desert of northern China. Scientists found that the dragonite contained properties related to "ether", an energy source that would allow spacecraft to travel faster than the speed of light, and thus traverse large distances of the universe in a short time. As new colonies were formed throughout the vast reaches of outer space, pirates, assassins, and outlaws began to threaten humanity's new frontier. To create order, the Earth Federation established four empires: USSA, Einhorn, Piotr, and Tenpa. However, internal power struggles within the factions and conflicts amongst one another become abundant, leading to inevitable lawlessness. The storyline starts shortly after an infamous outlaw named "Hot Ice" Hilda flees from the Kei Pirates, a branch of the Tenpa. Hilda has stolen from them a highly-advanced prototype ship dubbed the XGP15A-II and a suitcase containing a bio-android called Melfina, the only being capable of interfacing with the ship.

Outlaw Star opens on the backwater planet Sentinel III, on which the protagonist Gene Starwind and his 11-year-old business associate and best friend James "Jim" Hawking run a small jack-of-all-trades business. After the two take a job as bodyguards for a disguised Hilda and engage in a brief skirmish with the Kei Pirates, Gene and Jim find themselves the owners of the XGP15A-II (which they nickname the "Outlaw Star") and the caretakers of Melfina, though Hilda is killed in the process. Hilda reveals that the ship's true purpose is to locate the "Galactic Leyline" (銀河の龍脈, Ginga no Ryū Myaku; lit. "Galactic Dragon Vein"), a place which popular claims say is a holder of immense treasure, knowledge, and power. Throughout the course of the series, the crew grows to include the kimono-garbed contract killer "Twilight" Suzuka and the Ctarl-Ctarl alien catgirl Aisha Clanclan.

The Outlaw Star manga series and animated television series are paced differently. The anime episodes often involve Gene and his comrades taking on various jobs or missions to fund their ship's massive maintenance costs. Throughout their travels, the crew often encounters Ronald MacDougall and Harry MacDougall, a pair of bounty hunters responsible for the death of Gene's father. Ronald acts as a rival to Gene, while Harry wishes to form a bond with Melfina, a bio-android like himself, who instead develops strong feelings for Gene. The crew also contends with others that learn of the Outlaw Star's connection to the Galactic Leyline. They are Nguyen Khan, a scientist wishing to gain omniscience through the Leyline; and Lord Hazanko, the leader of the ruthless assassin organization the Anten Seven that seek the Leyline to gain ultimate power. The series climaxes when all parties meet on the physical plane of the Leyline. In the end, Ron MacDougall retreats, saved by a computer copy of his brother Harry (who is killed trying to protect Melfina from Hazanko), Khan is integrated into the Leyline as data, Gene reveals to Melfina that he is in love with her and frees her from the Leyline by making it their shared wish to be together forever, and Hazanko is eventually defeated by the Outlaw Star crewmembers. Once the conflict comes to a close, Gene and his friends return to Sentinel III and go their separate ways, but ultimately reunite to continue their adventures together.

Outlaw Star was created by Morning Star Studio. Takehiko Itō was the manga's director, writer, and chief artist. Itō was aided in his duties by Hajime Yatate, a pseudonym of writers at Sunrise. Others who contributed to the work include producer Kenzoh Tomita; starship designer Shoji Kawamori; character concept and imageboard illustrators Yutaka Minowa and Hajime Jinguji; and a team of production designers and assistant artists. Outlaw Star takes place in the Toward Stars Era, the same universe as Itō's Uchuu Eiyuu Monogatari (宇宙英雄物語; lit. "Space Hero Story"), a pulp-science fiction manga that was first serialized by Kadokawa Shoten in 1988. Itō has described this earlier work as "something out of boy's dream" and took a much more mature, scientific approach when writing Outlaw Star. The author also referenced aspects of Chinese culture when creating Outlaw Star.

The animated television series of Outlaw Star was produced by Sunrise and directed by Mitsuru Hongo, whose previous credits include the comedy Crayon Shin-chan and the magical girl series Shamanic Princess. The script was chiefly written by Katsuhiko Chiba [ja], who wrote about three-quarters of the episodes. Character designs were handled by Hiroyuki Hataike (Detonator Orgun, Armored Trooper Votoms) and Takuya Saito. The show's vehicles were designed by Juniya Ishigaki [ja] and Macross and Gundam mecha artist Shōji Kawamori, the latter of whom designed the Outlaw Star ship itself. Kow Otani composed the musical score for the Outlaw Star anime. The series features the opening theme "Through the Night" written and performed Masahiko Arimachi, and two closing themes, "Hiru no Tsuki" (昼の月; lit. "Daytime Moon") and "Tsuki no Ie" (月の家; lit. "House of the Moon"), both written and performed by Akino Arai. "Through the Night" was chosen for the opening among several candidate songs. Itō and Sunrise agreed that the theme should be one that had not been used in a recent animation and that it should feature male vocals. Arimachi wrote the song to resemble a story, took into account its long-term impact, and felt it fit Outlaw Star perfectly.