In the Babylon 5 science fiction saga, the Book of G'Kar was a book that was written by the Narn Ambassador G'Kar. The book is considered one Narn's most holy books. It also became one Narn's most popular books, along with other works such as the Book of G'Quan .

G'Kar began writing the book in 2260 while serving a six week prison sentence for his telepathic assualt on Ambassador Mollari. During the course of the assault, G'Kar had an epiphany when the Vorlon Ambassador, Kosh, connected with him telepathically. The experience changed G'Kar forever. He came to realize that some must be sacrificed for all to be saved - that the Narn must fight the larger fight even if it killed them all.

So while in prison, G'Kar began writing down what he had experienced during his revelation. G'Kar wrote how he and his people got to where they were, and what had to be done. What he thought would take a few weeks to finish wound up taking a large part of his life to finish. When G'Kar got out of prison, he continued to add to his book. He did this because of the additional things he had learned, and to correct some earlier chapters that he felt were written in anger.

G'Kar loaned the book to Michael Garibaldi for a time, but when Garibaldi returned the book, it had a coffee stain on it. Narn holy books are copied exactly from the original - every line and every mark is exactly copied. As a result those making the copies included a copy of the coffee stain ring on every copy of the book of G'Kar. When G'Kar confronted Garibaldi about the stain, Garibaldi replied that it was the best part of the book.

When G'Kar accompanied Mollari to Centauri Prime as his bodyguard, the Narn government took the book home to make copies because of fears that G'Kar would not return. The number of copies increased greatly, as did G'Kar's popularity among his own people. So many people came to see him that G'Kar felt a cult of personality had developed. When the Narn government wanted him to either return home to lead them, or return home to give his blessing for others to lead Narn, G'Kar decided to go away for a time. He and Lyta Alexander decided to go out and explore the galaxy for a few years until the fervor over him and his book subsided.