The Unwanted Undead Adventurer (Japanese: 望まぬ不死の冒険者, Hepburn: Nozomanu Fushi no Bōkensha) is a Japanese light novel series written by Yū Okano and illustrated by Jaian. It has been serialized online via the user-generated novel publishing website Shōsetsuka ni Narō since September 2016. It was later acquired by Overlap, who have published ten volumes since October 2017 under their Overlap Novels imprint.

A manga adaptation illustrated by Haiji Nakasone has been serialized in Overlap’s Comic Gardo website since November 2017, with its chapters collected into nine tankōbon volumes as of April 2022. An anime television series adaptation has been announced.

The Unwanted Undead Adventurer
First light novel volume cover
望まぬ不死の冒険者 (Nozomanu Fushi no Bōkensha)
Genre	Dark fantasy
Novel series
Written by	Yū Okano
Published by	Shōsetsuka ni Narō
Original run	September 22, 2016 – present
Light novel
Written by	Yū Okano
Illustrated by	Jaian
Published by	Overlap
English publisher	NA J-Novel Club
Imprint	Overlap Novels
Demographic	Male
Original run	October 25, 2017 – present
Volumes	10 (List of volumes)
Manga
Written by	Yū Okano
Illustrated by	Haiji Nakasone
Published by	Overlap
English publisher	NA J-Novel Club
Magazine	Comic Gardo
Demographic	Shōnen
Original run	November 24, 2017 – present
Volumes	9 (List of volumes)