The Ossan Newbie Adventurer, Trained to Death by the Most Powerful Party, Became Invincible (新米オッサン冒険者、最強パーティに死ぬほど鍛えられて無敵になる。, Shinmai Ossan Bōkensha, Saikyō Pāti ni Shinu Hodo Kitaerarete Muteki ni Naru) is a Japanese fantasy light novel series written by Kiraku Kishima and illustrated by Tea.

It was later acquired by Hobby Japan, which has published thirteen volumes since December 2018 under its HJ Novels imprint.

A manga adaptation with art by Ken Ogino has been serialized online via Hobby Japan's Comic Fire website since November 2019 and has been collected in nine tankōbon volumes.

Written by Kiraku Kishima, The Ossan Newbie Adventurer, Trained to Death by the Most Powerful Party, Became Invincible began serialization as a web novel published on the user-generated novel publishing site Shōsetsuka ni Narō, before moving to the Kakuyomu website on June 1, 2018.

[1] It was later revealed to be a television series, produced by Yumeta Company and directed by Shin Katagai, with scripts written by Kasumi Tsuchida, character designs handled by Mari Eguchi, and music composed by Tomotaka Ōsumi.