Given that the game's music was composed by Keiichi Okabe and his company MoNACA, it should hardly come as a surprise that it has an amazing OST.
- During the 3rd Anniversary of the Japanese server, Death's Feast
was added as new Colosseum BGM, and general consensus is that it's epic, especially when your guild is winning. - The theme for the Act of Fusion, O' Fusion's Song is a killer of a track, being different from most of the rest of the OST by having clear vocals and implementing more electronic elements as opposed to the usual orchestrals.
- Starting August 7, 2020, Trampling's Feast, a new Colosseum BGM, was added. What does it signify? The Act of Elimination, as the Colosseum walls split open to reveal the Reality world beyond Library, indicating the tougher battles ahead.
- The new music from the Act of Elimination trailer, Hymn of Elimination, is absolutely majestic, opening with a feeling of absolute menace before exploding into a audiotorial wave of epicness, all the while capturing the conflict to-be between the Characters' Reality and Library selves.
- Keiichi Okabe does it again with Strangling's Feast, the Colosseum BGM for the Act of Elimination. This menacing yet majestic music set gives off the feel of a Final Boss as the Colosseum battles go beyond the pages and take to the streets.
- If you thought "Banquet of Massacre" was epic, here's "Manic Depression of the Twin Puppets" which takes it up to eleven with a Death Metal arrangement. It's both epic and ridiculous in a way only SINoALICE could pull off, fitting for its 4th Anniversary. There's even a Death Metal medley that was performed during the corresponding livestream and even included Mafia Kajita as a guest vocalist with lyrics containing humor of the Self-Deprecation kind and fandom jokes galore.
- Passing=Anthem and Passing=Cry are songs only a privileged few get to enjoy as it serves as the themes of the World GranColosseum; hearing it is a mark of honor for being able to face off against the best of the best. On the official soundtrack, the latter clocks in at a whopping 10 minutes, making it the longest (and most epic) Colosseum theme in the game.
- "Lantern & Finale", the song used in the Act of Authors trailer, is filled with nostalgia for childhood innocence and perfectly symbolizes the Characters realizing the futility of their quest to revive their authors and have their wishes granted, slowly but surely losing whatever sanity they have left and falling into despair after finding out the truth of the SINoALICE System that the devious Parrah and Noya came up with.
- The music used in the Act of SINoALICE combines beatboxing with choral/operatic vocals and it somehow works. Appropriately, this music plays in the arc in which the Characters end up in our world and potentially have to fight Pokelabo themselves, with Elation/End, the trailer/final chapter boss theme, being a joyous chorus itself.
- Battle≠Salvation, an intense remix of "Banquet of Massacre" and "Battle Anthem" that plays during the Final Boss battle, serves as the fitting conclusion to this tale of pain and tragedy as everything is brought to a close.
- In contrast to the bombastic final battle theme, Comrades≠Remembrance is a mildly somber but at the same time hopeful tune similar to "Weight of the World" that is sure to bring a tear to the players' eyes given that the 6-year long journey is now over.
