A kigo is a word or phrase associated with a particular season, used in traditional forms of Japanese poetry. Kigo are used in the collaborative linked-verse forms renga and renku, as well as in haiku, to indicate the season referred to in the stanza. They are valuable in providing economy of expression.

Japanese poetry is poetry typical of Japan, or written, spoken, or chanted in the Japanese language, which includes Old Japanese, Early Middle Japanese, Late Middle Japanese, and Modern Japanese, as well as poetry in Japan which was written in the Chinese language or ryūka from the Okinawa Islands: it is possible to make a more accurate distinction between Japanese poetry written in Japan or by Japanese people in other languages versus that written in the Japanese language by speaking of Japanese-language poetry. Much of the literary record of Japanese poetry begins when Japanese poets encountered Chinese poetry during the Tang dynasty. Under the influence of the Chinese poets of this era Japanese began to compose poetry in Chinese kanshi); and, as part of this tradition, poetry in Japan tended to be intimately associated with pictorial painting, partly because of the influence of Chinese arts, and the tradition of the use of ink and brush for both writing and drawing. It took several hundred years to digest the foreign impact and make it an integral part of Japanese culture and to merge this kanshi poetry into a Japanese language literary tradition, and then later to develop the diversity of unique poetic forms of native poetry, such as waka, haikai, and other more Japanese poetic specialties. For example, in the Tale of Genji both kanshi and waka are frequently mentioned. The history of Japanese poetry goes from an early semi-historical/mythological phase, through the early Old Japanese literature inclusions, just before the Nara period, the Nara period itself, the Heian period, the Kamakura period, and so on, up through the poetically important Edo period and modern times; however, the history of poetry often is different from socio-political history.