The Halo novels are books about 340 pages each and have expanded heavily on the Halo Universe. The first three novels were published by Ballantine Books, while the two after that are published by Tor Books. Because of a 3-book contract by TOR, there is one more planned novel, but so far these are the only known novels:
- Halo: The Fall of Reach, this book explains what happened before Halo: Combat Evolved. By Eric Nylund.
- Halo: The Flood, the novelization of Halo: Combat Evolved by William C. Dietz. The Flood also features several side stories.
- Halo: First Strike, this book partially explains the SPARTAN Programs and fills in the gap between Halo: Combat Evolved and Halo 2. By Eric Nylund.
- Halo Box Set, the box set featuring the three first Halo Novels.
- Halo: Ghosts of Onyx, the book introducing Onyx. By Eric Nylund.
- Halo: Contact Harvest, features the events leading up to the Human-Covenant War. By Joseph Staten.
- Halo: The Cole Protocol, by Tobias S. Buckell, the book introducing Gray Team
There is also:
- Halo Graphic Novel, a comic book based on the Halo Universe.
- The Art of Halo, the Halo artists behind the scenes book.
- Halo: Combat Evolved: Sybex Official Strategies & Secrets, the official guide for Halo PC.
- Halo 2: The Official Game Guide, the official guide for Halo 2.
- Halo 3: The Official Guide, similar to Halo 2: The Official Game Guide, but with Halo 3.
- Halo: Uprising, Comic book series being made by Marvel Comics.
- Halo Wars: Genesis, prequal to Halo Wars.
Trivia
- In most of the novels, there is a Covenant subplot. These usually feature Grunts such as Yayap or Dadab.
- There is the Marathon symbol between the "A" and "L" of Halo on the cover of each novel.