John Ajvide Lindqvist (born 2 December 1968) is a Swedish writer renowned for his horror novels and short stories. He grew up in Blackeberg, the setting for his famous novel Let the Right One In. Before becoming a writer, Lindqvist aspired to create something both awful and fantastic, leading him first to become a conjurer and later a stand-up comedian for twelve years.

He has also contributed to Swedish television writing. His novel Let the Right One In was a bestseller in Sweden and received the accolade of Best Novel in Translation 2005 in Norway. Other notable works include Handling the Undead and Harbor.

He is married to author Mia Ajvide and is the father of author Fritiof Ajvide.