Seinen manga (青年漫画) are Japanese comics marketed toward young adult men. In Japanese, the word seinen literally means “youth”, but the term “seinen manga” is also used to describe the target audience of magazines like Weekly Manga Times and Weekly Manga Goraku which cater specifically to men’s interests, and are marketed towards a demographic of young adult men between the ages of 18 and 40. Seinen manga are distinguished from shōnen manga which are for younger teen boys. Seinen manga can focus on action, politics, science fiction, fantasy, relationships, sports, or comedy.

Seinen manga have a wide variety of art styles and variation in subject matter. Examples of seinen series include: Berserk, AKIRA, 20th Century Boys, One Punch Man, Golden Kamuy, Ghost in the Shell, Hellsing, Kingdom, Initial D, Maison Ikkoku, Master Keaton, Mushishi, Oh My Goddess!, Outlaw Star, and Tokyo Ghoul, as well as the formerly shōnen manga series JoJo’s Bizarre Adventure and Trigun.