Saga is an epic space opera/fantasy comic book series written by Brian K. Vaughan and illustrated by Fiona Staples, published monthly by the American company Image Comics. The series is based on ideas Vaughan conceived both as a child and as a parent. It depicts a husband and wife, Alana and Marko, from long-warring extraterrestrial races, fleeing authorities from both sides of a galactic war as they struggle to care for their daughter, Hazel, who is born in the beginning of the series, and who occasionally narrates the series as an unseen adult.

The comic was described in solicitations as "Star Wars meets A Game of Thrones", evocative of both science fiction and fantasy epics such as The Lord of the Rings, as well as classic works like Romeo and Juliet. It is Vaughan's first creator-owned work to be published through Image Comics, and is the first time he employs narration in his comics writing. Vaughan indicated that the entire series will span 108 issues, or chapters.

The first chapter of Saga was published on March 14, 2012, to positive reviews and a sold-out first printing. It was published in trade paperback form in October 2012. It has also been a consistent sales success, with its collected editions outselling those of The Walking Dead, another successful Image comic. The series went on hiatus after reaching its midpoint at Chapter 54 in July 2018, and resumed in January 2022.

The series has been met with wide critical acclaim, and is one of the most celebrated comics being published in the United States. It has also garnered numerous awards, including twelve Eisner and seventeen Harvey Awards between 2013 and 2017. The first trade paperback collection won the 2013 Hugo Award for Best Graphic Story. It has also been noted for its diverse portrayal of ethnicity, sexuality and gender social roles, and for its treatment of war.

Writer Brian K. Vaughan conceived Saga in his childhood, calling it "a fictional universe that I created when I was bored in math class. I just kept building it." He was inspired by such influences as Star Wars, Flash Gordon, and children's books, and has also invoked the awe and wonder of first seeing the Silver Surfer, which seemed an "incredible and different" concept to him. It was not until his wife became pregnant with his second daughter, however, that he conceived of the protagonists, the winged Alana and the horned Marko, two lovers from warring extraterrestrial races who struggle to survive with their newborn daughter, Hazel, who occasionally narrates the series. It was also at this point that the central theme that Vaughan wanted for the book emerged. Vaughan explains, "I wanted to write about parenthood, but I wanted to Trojan-horse it inside some sort of interesting genre story, to explore the overlap between artistic creation and the creation of a child." Vaughan, who intended to return to writing a comics series following the 2010 conclusion of his previous series, Ex Machina, and who notes that the publication of Saga #1 coincided with the birth of his daughter, saw parallels between the caution advised by colleagues against launching a new book in the poor economy and those who cautioned against bringing a new child into the world, observing:

I realized that making comics and making babies were kind of the same thing and if I could combine the two, it would be less boring if I set it in a crazy sci-fi fantasy universe and not just have anecdotes about diaper bags ... I didn't want to tell a Star Wars adventure with these noble heroes fighting an empire. These are people on the outskirts of the story who want out of this never-ending galactic war ... I'm part of the generation that all we do is complain about the prequels and how they let us down ... And if every one of us who complained about how the prequels didn't live up to our expectations just would make our own sci-fi fantasy, then it would be a much better use of our time.

Vaughan explained that the main characters' romance would be a major theme of the book. Touching upon the juxtaposition of the book's mature subject matter with its Star Wars inspirations, Vaughan jokingly described the book as "Star Wars for perverts."

The book was announced at the 2011 San Diego Comic-Con, and was billed as "Star Wars meets A Game of Thrones" in solicitations. Saga represents the first time Vaughan has employed narration in his comics writing, a decision influenced by the whimsical interaction between the text and images in the children's books he reads with his children, and by his desire to try something new that he felt would work well with Saga's narrator, Hazel. It is also his first series to be published through Image Comics, whom he selected as the series' publisher on the recommendation of the writer Jay Faerber, who cited the creative freedom afforded by that publisher. Vaughan elaborated on his selection of Image thus: