Known C'tan
Aza'gorod, the Nightbringer: The first C'tan to encounter the Necrons. Powerful enough to impress its image as that of death itself on the psyche of the younger races.
Death of Suns, enslaved by the Sautekh Dynasty. It serves as part of Gidrim's Blade of Gidrim Reclamation Legion.[43]
The Crimson God, enslaved by the Novokh Dynasty. It is commanded by the Novokh Overlord known as the Crimson King.[14]
Emberresh, the Suneater: Held captive by the Xonthar Dynasty, who use it as a weapon against their enemies.[13]
Hsiagn'la[18]
Iash'uddra, the Endless Swarm: The most reviled of the C'tan.
Kalugura, the Silent Cry: Entombed at the word of the Silent King
Llandu'gor, the Flayer: The only C'tan fully obliterated by the Necrons, in his death he cursed the Necrons with the flayer curse.
Mag'ladroth, the Void Dragon: A figure of oblivion, wanton destruction and devastation. Speculated to be the Dragon of Mars.[3]
Manubiarix - C'Tan shard contained within a black octohedron device. Currently in possession of Magos Explorator Isonovere Holt of Stygies VIII.[47]
Mephet'ran, the Deceiver: The C'tan who made the bargain to turn the Necrontyr into the Necrons.
N'phoran, the Spiral Flame[15]
Nyadra'zatha, the Burning One: A C'tan that gave the Necrons the ability to access the Webway.
Og'driada, the Arisen
Quantum Diggerlord[46]
Stardeath[11]
The Sufferer: Held captive on the Necron Tomb World of Silva Tenebris.[16]
Thyssak'lha, the Walking Blight[23]
Tsara'noga, the Outsider: A C'tan that went insane due to its consumption of other C'tan or possibly an Eldar deity.
Vesh-Kael, the Song of Oblivion[44]
Yggra'nya, the World Shaper: A C'tan whose very thoughts could break apart a planet and reshape it in a form more pleasing to him.[10]
Zarhulash, the Potentate: Used by the Necrons to power the Pharos.[17]
Zul'channec: A C'tan nearly awakened by a cabal of Crypteks[24]

Unnamed C'tan:
The C'tan rumored to be imprisoned within a satellite realm of Commorragh whose bled power lights the realm. The location of the realm is a mystery, but it is sought after by Drukhari, Alaitoc Aeldari, and ambitious Necron Overlords.[49]