Japanese jazz (Japanese: 日本のジャズ, Nihon no jazu) is jazz played by Japanese musicians or jazz connected to Japan or Japanese culture. According to some estimates, Japan has the largest proportion of jazz fans in the world.

Jazz was introduced to Japan in the 1910s through transpacific ocean liners, where Filipino musicians took influences from jazz, with the Philippines being an American colony at the time. Following the rise of the music recording industry, the lyrics of popular jazz records such as "The Sheik of Araby" and "My Blue Heaven" were translated into Japanese. Jazz was associated with Japanese counterparts to flappers and dandies and often played in dance halls. Although considered "enemy music" in Japan during World War II, due to its American roots, the genre was too popular for a ban, and many disobeyed the state-mandated destruction of jazz records.

During the occupation of Japan following World War II, there was a large demand for entertainment for American troops, and jazz was particularly popular. By the 1970s, the Japanese economic miracle paved the way for Japanese jazz musicians to achieve international fame, along with new musical genres such as city pop, kankyō ongaku, and Japanese folk music. Japanese jazz musicians also began to evolve past Blue Note mimicry and experimented with free jazz, fusion funk, and bebop, among others. This furthered the distinct sound of Japanese jazz. During the 1980s, digital music technology began to influence Japanese jazz.

In present-day Japan, jazz has become more of an alternative genre. It is no longer as popular, but retains the largest proportion of jazz fans in the world. Jazu Kissa (literally jazz café), dedicated spaces where aficionados gather to listen to jazz records, appeared in the 1950s and 60s. A phenomenon unique to the country, there are roughly 600 Jazu Kissa in present-day Japan, including some where conversation is prohibited. Recently, there has also been an increase in Jazu Kissa in rural areas. Contemporary Japanese jazz musicians include Hiromi Uehara, Kyoto Jazz Massive, United Future Organization and Soil & "Pimp" Sessions.

Jazz became popular in Japan in the 1920s, following visits by bands from America and the Philippines, where American popular music had been introduced by the occupying forces. The Hatano Jazz Band is sometimes described as the first Japanese jazz band, although they were primarily a dance band. The band, which was created in 1912 by graduates from Tokyo Music School, absorbed and performed American dance music after traveling to San Francisco, but their music did not claim to feature jazz improvisation.

Local jazz practice, built around the performances of visiting Filipinos, began to emerge in the early 1920s, most notably in the prosperous entertainment districts of Osaka and Kobe. By 1924, the city of Osaka already boasted twenty dance halls, which gave many Japanese-born musicians an opportunity to play jazz professionally. Trumpeter Fumio Nanri (1910–1975) was the first of these Japanese jazz performers to gain international acclaim for his playing style. In 1929 Nanri traveled to Shanghai, where he played with American jazz pianist Teddy Weatherford, and in 1932 he toured in the United States. After his return to Japan, Nanri made several recordings with his band Hot Peppers, an American-style swing band.

The "Americanness" and mass appeal of early jazz as dance music gave reason for concern among the conservative Japanese elite, and in 1927 Osaka municipal officials issued ordinances that forced the dance halls to close. A large number of young musicians switched to the jazz scene in Tokyo, where some found employment in the house jazz orchestras of the major recording companies.

In 1933 Chigusa, Japan's surviving oldest jazz cafe, or Jazu kissa, opened in Yokohama. Since then, jazz coffeehouses have provided a popular alternative to the dance hall, offering the latest jazz records (while occasionally also hosting live performances) to an attentively listening audience. In the 1930s, popular song composers Ryoichi Hattori and Koichi Sugii tried to overcome jazz music's controversial qualities by creating a distinctively Japanese kind of jazz music. They reworked ancient Japanese folk or theatre songs with a jazz touch, and in addition wrote new jazz songs that had Japanese thematic content and often closely resembled well-known traditional melodies. Hattori's songs, however, flirted with controversy, most notably in his 1940 Shortage Song (タリナイ・ソング, Tarinai songu), which he wrote for Tadaharu Nakano's Rhythm Boys. Satirizing the shortages of food and material then widespread in Japan, the song drew the ire of government censors and was quickly banned. The controversy was among the factors that led to the Rhythm Boys' breakup in 1941.