Forgotten Realms, based on Babylonian:
[*]Gilgeam: Former god of battle, prowess, strength. Slain by Tiamat.
[*]Girru: Slain by an unnamed orc deity.
[*]Inanna: Former Goddess of War and Love. Slain by an unnamed orc deity.
[*]Ki: Former Spirit/mother-goddess of the Earth. Slain by an unnamed orc deity.
[*]Marduk: Slain by an unnamed orc deity.
[*]Nanna-Sin: Former God of The Moon and protection against Evil. Slain by an unnamed orc deity.
[*]Nergal: Former god of the underworld. Slain by an unnamed orc deity.
[*]Ramman: Former god of duty, order, vigilance, war. Slain by Hoar.
[*]Utu: Former God of the Sun and Justice. Slain by an unnamed orc deity.
Forgotten Realms, other:
[*]Amaunator (also called At'ar): Former god of bureaucracy, law, order, the sun. Faded from lack of worship. Reappears as an evolving aspect of Lathander.
[*]Auppenser, also known as "Our Lord of Reason", "The Master of Thought", and "The Serene One", is the deity of Balance, Mentalism, Protection, Psionics, and Strength. He is initially relatively powerful, worshiped by human and demihuman psions, monks, and psychic warriors, and all manner of psionic creatures such as blues and duergar. After the collapse of Jhaamdath, his main place of worship, he loses most of his followers and goes into a deep slumber to keep existing. Auppenser is a strong-minded deity given over as much to deep contemplation as he is to decisive action. The god of psionics possesses a calm demeanor, as one completely confident in his clear-thinking ways. He strives to uphold the Balance wherever psionics are involved.
[*]Bhaal: Former god of assassination, murder, violence. Slain by Cyric and Mask.
[*]Chronos: Former god of time.
[*]Earthmother: Former goddess of life. Slain by Bhaal.
[*]Eshowdow: Former god of Chult. Slain by Shar.
[*]Ibrandul: Former god of Caverns, dungeons, skulks. Slain by Shar.
[*]Iyachtu Xvim: Former god of tyranny, hatred, fear. Destroyed by Bane during his return.
[*]Jazirian: Former god of couatls. Slain by Merrshaulk.
[*]Kalzareinad: Former god of the uncaring, evil, or selfish application of dragon magic. Slain by Kareska.
[*]Karsus: very briefly (a matter of minutes) a former god of magic and hubris, after, as a mortal man, he stole the powers of the first goddess of magic with a powerful magical spell, which caused magic to cease during his attempt. Died following the sacrifice of Mystryl to restore the proper functioning of magic in the Realms. Known as the 'Momentary God'.
[*]Kiputytto: Former goddess of sickness. Slain by Talona.
[*]Kukul: Former Maztican god of creation
[*]Leira: Former goddess of deception, illusion, mist and shadow. Slain by Cyric and Mask.
[*]Moander: Former god of decay, corruption, rot. Slain by Finder Wyvernspur.
[*]Murdane: Former goddess of reason, pragmatism. Slain during the Dawn Cataclysm.
[*]Myrkul: Former god of corruption, the dead, death, old age. Slain by Mystra.
[*]Mystra: The reincarnated Mystryl and former goddess of magic, spells, and the Weave. Slain by Helm during the Time of Troubles and replaced by the mortal woman Midnight (who now goes by Mystra's name).
[*]Mystryl: Original goddess of magic created by the combined essences of Selûne and Shar. Sacrificed herself to repair the damage caused by Karsus's ascension.
[*]Othea: Former goddess of giants, motherhood. Slain by Lanaxis, one of her children.
[*]Ra: Former Mulhorandi god of the sun. Slain by Gruumsh.
[*]The Seven Lost Gods, all of whom "bowed down before Bane", including:
- Camnod the Unseen
- Borem of the Lake of Boiling Mud: Former god of anger
- Haask, the Voice of Hargut
- Maram of the Great Spear
- Tyranthraxus the Flamed One
[*]Tyche: Former goddess of luck. Split into Beshaba and Tymora.
[*]Valigan Thirdborn: Former god of anarchy. Slain by Tyr.
[*]World Serpent: Former god of the sarrukh. Fragmented into the deities of the lizardfolk, naga, and yuan-ti.
Midkemia (novels, based on a D&D game, so kind of counts):
[*]Drusala - Goddess of Healing. (Sung reigns in her sister's place)
[*]Eortis - God of the Sea. (Killian reigns in his place)
[*]Isanda - Goddess of dance
[*]Onanka-Tith - the dead half of Tith-Onanka
[*]Sarig - "Lost" God of Magic.
[*]Wodar-Hospur - God of Knowledge; the Lorekeeper. (Banath is custodian in his place)
4E:
[*]Amoth - God of Justice and Mercy. Killed by the demon princes Orcus, Demogorgon and Rimmon.
[*]Gorellik - God of Hunting, Beasts, and Gnolls. Killed by the demon lord Yeenoghu.
[*]He Who Was - A god of good and possibly peace, he was killed by his archangel and exarch, Asmodeus. Implied to be the creator of humans, the devils wiped out all knowledge of his name, which they fear is powerful enough to revive him if it is ever spoken aloud again. The Nine Hells were originally his astral domain, now a prison for Asmodeus and his devils. A holy chalice belonging to him is mentioned in Divine Power.
[*]Khala - Goddess of Winter, wife of Zehir, mother of Kord, Khala sought to trap the natural world in an eternal winter to secure power over it. Her plans convinced the primal spirits to expel gods and primordials from the world. She was killed by the other gods in a conflict called the War of Winter, who afterwards made a compact to balance darkness and light (Zehir and Pelor), and the natural seasons (Corellon, Pelor and Sehanine). Her power over winter was taken by the Raven Queen.
[*]Lakal- God of Healing and Mercy who was also her own Astral Dominion. She was an impersonal deity who communicated with her chosen people, the Quom, through "ecstatic moments of personal communion." She extolled mercy and urged her followers to dedicate themselves to pursuits that benefitted the whole cosmos. Lakal's death was accidental- when Bahamut battled Nihil, the Primoridial of nothingness, the pair crashed into Lakal. Bahamut was able to use the distraction to slay Nihil, but the primoridal's death throes also caused Lakal to explode. The surviving quom now roam the planes, retrieving any shards of Lakal that they can find, including those unknowingly consumed by living creatures. Such creatures, including humanoids and player characters, are considered collateral damage in the quom's quest to restore Lakal. Ironically, even if the quom succeed in their quest, the restored Lakal would be disgusted with their methods.
[*]Maglubiyet - God of Goblinoids. Defeated by Bane.
[*]Nerull - God of Death and the Dead. Killed by The Raven Queen.
[*]Tuern - God of War. Killed by Bane.
[*]Nusemnee - Nusemnee was the daughter of Zehir and a powerful devil. When she failed to assassinate a high priest of Pelor, she was abandoned and then mortally wounded by a paladin’s holy blade. Expecting only death, she was surprised when the high priest healed her, showing her compassion and forgiveness. Intrigued, she decided to honor a promise to the high priest and aid him in his holy quest until a time that she could save his life in turn. Nusemnee thus became a symbol of redemption. When she finally died at the end of the high priest’s quest, she rose again, this time as a minor goddess. In this form, she opposed her father by offering redemption to all who would turn away from evil. She was later killed by a poison that could kill anything—even a deity—that was distilled from Zehir’s blood.