The High Priest Not to be Described is a character in H. P. Lovecraft's Cthulhu Mythos. He wears a yellow silken mask and is first mentioned in the Lovecraft story "The Dream Quest of Unknown Kadath". The priest dwells uncompanioned in the remote and prehistoric monastery and prays to the Other Gods and their crawling chaos Nyarlathotep.

The only description Lovecraft offers of the character is the passage:

"And there on a golden throne sat a lumpish figure robed in yellow silk with red and having a yellow silken mask over its face. To this being the slant-eyed man made certain signs with his hands, and the lurker in the dark replied by raising a disgustingly carven flute of ivory in silk covered paws and blowing certain loathesome sounds from beneath its flowing silken mask."