There are twelve volumes in the main novel series, written by Gatoh Shouji, illustrated by Shikidouji. Full Metal Panic ran in Gekkan Dragon Magazine, a monthly magazine for light novels, starting September 1998. The original English releases of books 1-5 were translated and published by Tokyopop. The current English release is from J-Novel Club; they're available individually as ebooks or as the hardcover 3-in-1 Collector's Editions. The final Collector's Edition, containing books 10-12, will be released Summer 2022.
Book One, originally released December 1998. The original English release by Tokyopop was September 2007.
Summary: "A boy comes from the battlefield to protect a girl holding a secret from villainous terrotists. But because of his tragic background, his battle-crazy tendencies are totally out of place in a peaceful high school setting! What cruel fate awaits these two?" [Translated directly from "Super Guide Full Metal Panic! 2007"]
Season One, episodes 1-7 of the anime -- It was later adapted into the "Fighting Boy Meets Girl Director's Cut" movie.
Book Two, originally released March 1999. The original English release by Tokyopop was January 2008.
Summary: (by Memento) Mithril attempts to track down a terrorist organization known as A21, which somehow leads Tessa to Sousuke's apartment with A21's young AS pilot Takuma. Due to several misunderstandings, Kaname gets unwillingly wrapped up in the situation. It comes down to Sousuke, Kaname, Tessa, and Kurz to take down an AS so massive it shouldn't even exist before it destroys Tokyo!
Season one, episodes 10-13 of the anime -- It was later adapted into the "Running One Night Stand Director's Cut" movie.
Book Three, originally released February 2000. The original English release by Tokyopop was June 2008.
Summary: (temporarily by Memento once again) Sousuke invites Kaname on a short trip at the beginning of summer vacation, only for the two of them to be dragged onto the Danaan because of an incident on a nearby island. After celebrating de Danaan's birthday, Sousuke and the rest of the SRT are sent to liberate the island from terrorists only to find Gauron working alongside them! Despite losing the fight and being taken aboard the Danaan as prisoner, Gauron seems totally relaxed, putting Tessa and the crew on edge. An argument between Kaname and Sousuke causes them to separate right before disaster strikes.
Book Four, originally released November 2000. The original English release by Tokyopop was February 2011 (it was published as a single volume with Ending Day By Day: Lower). It was adapted into Full Metal Panic: The Second Raid episodes 1-7 (although the first few episodes are anime-only added material).
Summary: Sousuke's balancing act between acting as an on-call mercenary for Mithril and a student by day is starting to take a toll on him and he's the only one that can't see it. Mao encourages him to take a serious look at his future, but despite enjoying his life as a student, he still doesn't feel like he's acclimated. Right as he and Kaname get closer, his mission to protect her is ended and he's called back to the base, never to contact Kaname again. Meanwhile, Kaname is starting to get the feeling she's being watched by someone, and it might not be just Mithril's mysterious spy.
Book Five, originally released April 2001. Adapted into the second half of Full Metal Panic: The Second Raid.
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Book Six, originally released March 2003. It hasn't been animated, but there's an audio drama adaptation.
Book Seven, originally released October 2004. Adapted into episodes 1-4 of Full Metal Panic: Invisible Victory.
Book Eight, originally released January 2006.
Book Nine, originally released March 2007.
Book Ten, originally relased February 2008. Has not been animated.
Book Eleven, Originally released July 2010. Has not been animated.
Book Twelve, originally released August 2010. Has not been animated.
Despite not having a canon order, because of events in the main story, it can be assumed that any side story where Sousuke and Kaname are attenting Jindai HS takes place between April 20th 1998 to sometime in January 1999. If you combine anime/novel canons, any of the stories here adapted in Fumoffu!? or the first season would take place between August and September 1998 (2001 if you're going by anime time)! Several of them have been adapted in the manga, but not the anime. These have not been officially translated into English, although you can find some fan translations online.
Side Story Book One, originally published December 1998
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Side Story Book Two, originally published May 1999.
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Side Story Book Three, originally published October 1999.
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Originally published June 2000
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Originally published October 2001.
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Originally published June 2002.
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Originally Published July 2003.
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Originally published April 2004.
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Originally published July 2005.
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Originally published July 2006.
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Originally publised August 2011 Featuring:
(WIP)