Kat Richardson (born May 22, 1964) is an American author best known for her Greywalker urban fantasy series.

She is married and lives in Seattle, Washington, and is an advocate of California Ferret Legalization.

"[2] Harper Blaine, the heroine of the series, is a private investigator living in Seattle and was killed whilst pursuing a case.

During her recovery, she discovers she is able to recognize witches and vampires, see ghosts and is aware of other elements of the supernatural world .

She discovers that her brief death has turned her into a Greywalker, a human able to move back and forth at will through the Grey, the realm that exists between our world and the next.