Boss Music is used numerous times in the Kingdom Hearts series to indicate that the current battle is with a boss. Most Boss Music is fast-paced and sends a theme of evil or tension. Usually the same song would be used in different boss battles to show the connection between them, i.e Shrouding Dark Cloud is associated with Heartless Bosses and Squirming Evil is used commonly for Disney Bosses in Kingdom Hearts.
Kingdom Hearts
Awakening
- Darkside - Dive into the Heart (Destati)
Destiny Islands
- Darkside - Destiny's Force
Traverse Town
- Leon - Night of Fate
- Guard Armor - Shrouding Dark Cloud
- Opposite Armor - Destiny's Force
Wonderland
- Queen of Hearts, Card Soldiers and Crank Tower - To Our Surprise
- Trickmaster - Shrouding Dark Cloud
Olympus Coliseum
- Cloud (Story) - Shrouding Dark Cloud
- Cerberus (Story) - Squirming Evil
- Hades - Squirming Evil
- Rock Titan - The Deep End
- Ice Titan - The Deep End
- Sephiroth - One-Winged Angel (from Final Fantasy VII)
Deep Jungle
- Sabor - Having a Wild Time
- Clayton and Stealth Sneak - Squirming Evil
Agrabah
- Pot Centipede - Shrouding Dark Cloud
- Cave of Wonders Guardian - Arabian Dreams
- Jafar (1st Battle) - Squirming Evil
- Jafar (Genie) - Destiny's Force
- Kurt Zisa - The Deep End
Monstro
- Parasite Cage (1st Battle) - Shrouding Dark Cloud
- Parasite Cage (2nd Battle) - Destiny's Force
Atlantica
- Ursula - Squirming Evil
- Giant Ursula - The Deep End
Halloween Town
- Lock, Shock and Barrel - Spooks of Halloween Town
- Oogie Boogie (1st Battle) - Squirming Evil
- Oogie Boogie (2nd Battle) - Destiny's Force
Neverland
- AntiSora - Shrouding Dark Cloud
- Captain Hook - Squirming Evil
- Phantom - Destiny's Force
Hollow Bastion
- Riku (1st Battle) - Scherzo Di Notte
- Maleficent (1st Battle) - Squirming Evil
- Maleficent (Dragon) - The Deep End
- Riku (2nd Battle) - Forze del Male
- Behemoth - Destiny's Force
World Terminus
- Chernabog - A Night on the Bald Mountain
End of the World
- Ansem (1st Battle) - The Deep End
- Darkside - Destiny's Force
- Ansem (2nd Battle) - Forze del Male
- World of Chaos - Guardando Nel Buio
Kingdom Hearts Final Mix
Hollow Bastion
- Unknown - Disappeared
Kingdom Hearts: Chain of Memories
Sora Mode
Traverse Town
- Guard Armor - Struggle Away
Wonderland
- Card Soldiers - To Our Surprise
- Trickmaster - Struggle Away
Olympus Coliseum
- Cloud - Go For It!
- Hades - The Fight for my Friends
Agrabah
- Jafar - The Fight for my Friends
Monstro
- Parasite Cage - Struggle Away
Halloween Town
- Oogie Boogie - The Fight for my Friends
Atlantica
- Ursula - The Fight for my Friends
Neverland
- Captain Hook - The Fight for my Friends
Hollow Bastion
- Maleficent - The Fight for my Friends
Destiny Islands
- Darkside - Struggle Away
Simulated Twilight Town
- Vexen (2nd Battle) - The 13th Struggle
Castle Oblivion
- Axel (1st Battle) - The 13th Struggle
- Larxene (1st Battle) - The 13th Struggle
- Riku Replica (1st Battle) - The Force in You
- Riku Replica (2nd Battle) - The Force in You
- Vexen (1st Battle) - The 13th Struggle
- Riku Replica (3rd Battle) - The Force in You
- Riku Replica (4th Battle) - The Force in You
- Larxene (2nd Battle) - The 13th Struggle
- Axel (2nd Battle) - The 13th Struggle
- Fake Marluxia (1st Battle) - Graceful Assassin
- Marluxia (Second Form) (2nd Battle) - Scythe of Petals
Riku Mode
Hollow Bastion
- Maleficent - The Fight for my Friends
Traverse Town
- Guard Armor - Struggle Away
Agrabah
- Jafar - The Fight for my Friends
Monstro
- Parasite Cage - Struggle Away
Neverland
- Captain Hook - The Fight for my Friends
Wonderland
- Trickmaster - Struggle Away
Olympus Coliseum
- Hades - The Fight for my Friends
Atlantica
- Ursula - Face It!
Halloween Town
- Oogie Boogie - The Fight for my Friends
Destiny Islands
- Darkside - Struggle Away
Simulated Twilight Town
- Riku Replica (2nd Battle) - The Force in You
Castle Oblivion
- Vexen - The 13th Struggle
- Riku Replica (1st Battle) - The Force in You
- Lexaeus - The 13th Struggle
- Ansem - Revenge of Chaos
Kingdom Hearts Re:Chain of Memories
Sora Mode
Castle Oblivion
- Marluxia (Third Form) - Lord of the Castle
Riku Mode
Destiny Islands
- Zexion - The 13th Struggle
Kingdom Hearts II
Roxas
Awakening
- Twilight Thorn - Tension Rising
Simulated Twilight Town
- Axel (1st Battle) - The 13th Struggle
- Axel (2nd Battle) - The 13th Struggle
Sora
Hollow Bastion
- Demyx (2nd Battle) - The 13th Dilemma
Radiant Garden
- Sephiroth - One Winged Angel (For Final Fantasy VII)
Land of Dragons
- Shan Yu - Vim & Vigor
- Storm Rider - The Corrupted
Beast's Castle
- Possessor/Thresholder - Dance to the Death
- The Beast - Tension Rising
- Shadow Stalker - Dance to the Death
- Dark Thorn - Desire for All That Is Lost
- Xaldin - The 13th Dilemma
Underworld
- Cerberus - Vim and Vigor
- Demyx (1st Battle) - Tension Rising
- Pete (1st Battle) - Rowdy Rumble
- Hades - The Encounter
Olympus Coliseum
- Hydra - Desire for All That Is Lost
Timeless River
- Pete (Timeless River) - Rowdy Rumble
- Pete (2nd Battle) - Rowdy Rumble
- Pete (3rd Battle) - Desire for All That Is Lost
Port Royal
- Captain Barbossa and Illuminator - Vim and Vigor
- Grim Reaper (1st Battle) - Sinister Shadows
- Grim Reaper (2nd Battle) - The Corrupted
Agrabah
- Volcanic Lord and Blizzard Lord - Desire for All That Is Lost
- Jafar - The Encounter
Halloween Town
- Prison Keeper and Lock, Shock and Barrel - Dance to the Death
Christmas Town
- Oogie Boogie - The Encounter
- Lock, Shock and Barrel - Rowdy Rumble
- The Experiment - The Corrupted
Pride Lands
- Shenzi, Banzai, and Ed (1st Battle) - Rowdy Rumble
- Scar - The Encounter
- Shenzi, Banzai, and Ed (2nd Battle) - Rowdy Rumble
- Groundshaker - The Corrupted
Space Paranoids
- Hostile Program - The Corrupted
- Sark - Sinister Shadows
The World that Never Was
- Xigbar - The 13th Dilemma
- Luxord - The 13th Struggle
- Saïx - The 13th Dilemma
- Xemnas - Disappeared
- Xemnas (Dragon) - Darkness of the Unknown
- Xemnas (Dragon) (2nd Battle) - Darkness of the Unknown
- Xemnas (Final) - Darkness of the Unknown
Kingdom Hearts
- Xemnas (Armor) (1st Battle) - A Fight to the Death
Kingdom Hearts II Final Mix
The Gathering Place
- Lingering Sentiment - Rage Awakened
Cavern of Remembrance
- Xemnas Data Battles - Disappeared and Darkness of the Unknown
- Xigbar, Xaldin, Saïx and Demyx Data Battles - The 13th Dilemma
- Vexen, Lexaeus, Zexion, Marluxia and Larxene Data Battles - The 13th Reflection
- Axel and Luxord Data Battles - The 13th Struggle
- Roxas Data - The Other Promise
The World that Never Was
- Organization XIII - The Other Promise
Various
- All Absent Silhouettes - The 13th Refection (Agrabah (Vexen), Twilight Town (Lexaeus), Underworld (Zexion), Beast's Castle (Marluxia), Port Royal (Larxene))
Kingdom Hearts 358/2 Days
Twilight Town
- Guardian - Tension Rising
- Veil Lizard - Shrouding Dark Cloud
- Tailbunker - Tension Rising (most minibosses have this as their music)
- Darkside - Destiny's Force
- Powered Armor - Tension Rising
Agrabah
Beast's Castle
- Dark Follower - Destiny's Force
- Infernal Engine - Vim and Vigor
Olympus Coliseum
- Morning Star - Tension Rising
- Guard Armor - Shrouding Dark Cloud
Wonderland
- Lurk Lizard -
- Crimson Prankster -
- Xion Form 1 - Shrouding Dark Cloud
Never Land
- Wavecrest - Tension Rising
- Ruler of the Sky -
Halloween Town
- Leechgrave - Vim and Vigor
- Xion Form 2 - Vim and Vigor
Various
- Here there be spoilers?