Doujinshi (同人誌), also romanized as dōjinshi, is the Japanese term for self-published print works, such as magazines, manga, and novels. Part of a wider category of doujin (self-published) works, doujinshi are often derivative of existing works and created by amateurs, though some professional artists participate in order to publish material outside the regular industry.

Groups of doujinshi artists refer to themselves as a sākuru (サークル, circle). Several such groups actually consist of a single artist: they are sometimes called kojin sākuru (個人サークル, personal circles).

Since the 1980s, the main method of distribution has been through regular doujinshi conventions, the largest of which is called Comiket (short for "Comic Market") held in the summer and winter in Tokyo's Big Sight. At the convention, over 20 acres (81,000 m²) of doujinshi are bought, sold, and traded by attendees.

The term doujinshi is derived from doujin (同人, literally "same person"; used to refer to a person or people with whom one shares a common goal or interest) and shi (誌; a suffix generally meaning "periodical publication").

The pioneer among doujinshi was Meiroku zasshi (明六雑誌), published in the early Meiji period (since 1874). Not a literary magazine in fact, Meiroku Zasshi nevertheless played a big role in spreading the idea of doujinshi. The first magazine to publish doujinshi novels was Garakuta Bunko (我楽多文庫), founded in 1885 by writers Ozaki Kōyō and Yamada Bimyo. Doujinshi publication reached its peak in the early Shōwa period, and doujinshi became a mouthpiece for the creative youth of that time. Created and distributed in small circles of authors or close friends, doujinshi contributed significantly to the emergence and development of the shishōsetsu genre. During the postwar years, doujinshi gradually decreased in importance as outlets for different literary schools and new authors. Their role was taken over by literary journals such as Gunzo, Bungakukai and others. One notable exception was Bungei Shuto (文芸首都; lit. Literary Capital), which was published from 1933 until 1969. Few doujinshi magazines survived with the help of official literary journals. Haiku and tanka magazines are still published today.

It has been suggested that technological advances in the field of photocopying during the 1970s contributed to an increase in publishing doujinshi. During this time, manga editors were encouraging manga authors to appeal to a mass market, which may have also contributed to an increase in the popularity of writing doujinshi.

During the 1980s, the content of doujinshi shifted from being predominantly original content to being mostly parodic of existing series. Often called aniparo, this was often an excuse to feature certain characters in romantic relationships. Male authors focused on series like Urusei Yatsura, and female authors focused on series like Captain Tsubasa. This coincided with the rise in popularity of Comiket, the first event dedicated specifically to the distribution of doujinshi, which had been founded in 1975.

By February 1991, there were some doujinshi creators who sold their work through supportive comic book stores. This practice came to light when three managers of such shops were arrested for having a lolicon doujinshi for sale.