Okinawan (沖縄口, ウチナーグチ, Uchināguchi, [ʔut͡ɕinaːɡut͡ɕi]), or more precisely Central Okinawan, is a Northern Ryukyuan language spoken primarily in the southern half of the island of Okinawa, as well as in the surrounding islands of Kerama, Kumejima, Tonaki, Aguni and a number of smaller peripheral islands. Central Okinawan distinguishes itself from the speech of Northern Okinawa, which is classified independently as the Kunigami language. Both languages are listed by UNESCO as endangered.

Though Okinawan encompasses a number of local dialects, the Shuri–Naha variant is generally recognized as the de facto standard, as it had been used as the official language of the Ryukyu Kingdom since the reign of King Shō Shin (1477–1526). Moreover, as the former capital of Shuri was built around the royal palace, the language used by the royal court became the regional and literary standard, which thus flourished in songs and poems written during that era.

Today, most Okinawans speak Okinawan Japanese, although a number of people still speak the Okinawan language, most often the elderly. Within Japan, Okinawan is often not seen as a language unto itself but is referred to as the Okinawan dialect (沖縄方言, Okinawa hōgen), or more specifically the Central and Southern Okinawan dialects (沖縄中南部諸方言, Okinawa Chūnanbu Sho hōgen). Okinawan speakers are undergoing language shift as they switch to Japanese, since language use in Okinawa today is far from stable. Okinawans are assimilating and accenting standard Japanese due to the similarity of the two languages, the standardized and centralized education system, the media, business and social contact with mainlanders and previous attempts from Japan to suppress the native languages. Okinawan is still kept alive in popular music, tourist shows and in theaters featuring a local drama called uchinā shibai, which depict local customs and manners.

Okinawan is a Japonic language, derived from Proto-Japonic and is therefore related to Japanese. The split between Old Japanese and the Ryukyuan languages has been estimated to have occurred as early as the 1st century AD to as late as the 12th century AD. Chinese and Japanese characters were first introduced by a Japanese missionary in 1265.

Hiragana was a much more popular writing system than kanji; thus, Okinawan poems were commonly written solely in hiragana or with little kanji. Okinawan became the official language under King Shō Shin. The Omoro Sōshi, a compilation of ancient Ryukyuan poems, was written in an early form of Okinawan, known as Old Okinawan.

After Ryukyu became a vassal of Satsuma Domain, kanji gained more prominence in poetry; however, official Ryukyuan documents were written in Classical Chinese. During this time, the language gradually evolved into Modern Okinawan.

In 1609, the Ryukyu Kingdom was colonized by the Satsuma Domain in the south of Japan. However, Satsuma did not fully invade the Ryukyu in fear of colliding with China, which had a stronger trading relationship with the Ryukyu at the time.

When Ryukyu was annexed by Japan in 1879, the majority of people on Okinawa Island spoke Okinawan. Within 10 years, the Japanese government began an assimilation policy of Japanization, where Ryukyuan languages were gradually suppressed. The education system was the heart of Japanization, where Okinawan children were taught Japanese and punished for speaking their native language, being told that their language was just a "dialect".