Character mentioned in the song The Court of the Crimson King by the band King Crimson (see Music for more details), which is sometimes loosely linked to The Hastur Mythos.
- The name has been adopted by Stephen King for a character with some similarities to The King In Yellow in his The Dark Tower series of novels. The Crimson King even has a symbol, a red eye, that has some similarity to The Yellow Sign. Dwells within the Dark Tower.
- A Crimson King sleeps below the unnamed city in The Old One & The Star Spawn and when it rises up, the moon will crack and release the Old One that dwells beneath it, ending the world.
- See the non-Mythos novel In The Courts of the Crimson Kings.
- Magnus the Red in Warhammer 40,000 is known as the Crimson King, as is a Necron Overlord.
- Crimson King is the title of a non-Mythos bizarro novel by JB Rockwell.