Events in the year 1926 in Japan. In the history of Japan, it marks the final year of the Taishō period, Taishō 15 (大正15年), upon the death of Emperor Taishō on December 25, and the beginning of the Shōwa period, Shōwa 1, (昭和元年), upon the accession of his son Emperor Shōwa (Hirohito). In the Japanese calendar Shōwa 1 was just six days long, prior to January 1 Showa 2 (1927, 昭和2年).

• Emperor:
  • Taishō: until December 25^[1]
  • Shōwa: starting December 25^[2]
• Regent: Hirohito until December 25
• Prime Minister:
  • Katō Takaaki: until January 28
  • Wakatsuki Reijirō: starting January 30

• January 12 – Toray (then Toyo Rayon) was founded.^{[page needed]}
• January 28 – Prime Minister Katō Takaaki dies in office. Wakatsuki Reijirō serves as acting Prime Minister until assuming the office proper on January 30.
• March 12 – Japanese warship bombards the Taku Forts in China, killing several Guominjun troops guarding the forts. Guominjun troops fired back in retaliation and drive the warship out of the Tanggu harbor.
• May 24 – A volcano eruption hit in Mount Tokachi, Hokkaido, according to Japanese government official document figure showed, 144 persons were fatalities, 21 persons missing, about 200 persons were hurt.^{[page needed]}
• June 10 – June 10th Movement: public displays of Korean resistance organized by students against Japanese rule take place in Korea.
• June 12 – The Japan Amateur Radio League, national non-profit organization for amateur radio enthusiasts, is founded by Japanese radio communication enthusiasts whose stated aim was to promote the development and utilization of radio wave technology as a medium.
• June 23 – Kuraray, (then Kurashiki Rayon) founded in Kurashiki, Okayama Prefecture.^{[page needed]}
• September 15 – Toshimaen, a representative amusement park in Tokyo was officially open, where closed on 31 August 2020, convert into a Harry Potter new theme park replace in March 2023.^{[citation needed]}
• September 16
  • Shin-Etsu Chemical founded in Nagano City.^{[page needed]}
  • Mikasaya Department Store, as predecessor of Kintetsu Department Store Osaka Uehonmachi was officially open in Tennoji-ku, Osaka.^{[page needed]}
• October 23 – Meiji Jingu Stadium was officially open.^{[citation needed]}
• November 18 – Inventor and industrialist Sakichi Toyoda founds the Toyota Industries, the company from which Toyota Motor Corporation would develop.
• December 25 – Emperor Taishō dies and is succeeded by his son Hirohito who becomes Emperor Shōwa. This event marks the end of the Taishō period and the beginning of the Shōwa period. Emperor Shōwa reigned as Emperor of Japan until his death in 1989.
• Unknown date – Nippon Shokubai (Catalyst) was founded, as predecessor name was Yosame Sulfuric Acid Industry.^{[page needed]}

• January 8 – Hanae Mori, fashion designer (d. 2022)
• January 12 – Shumon Miura, writer (d. 2017)
• January 25 – Gaisi Takeuti, mathematician (d. 2017)
• February 5 – Seiichi Miyake, inventor (d. 1982)
• February 7 – Keiko Tsushima, actress (d. 2012)
• February 24 – Kōno Taeko, writer (d. 2015)
• February 25 – Akira Tago, psychologist (d. 2016)
• February 28 – Kin Sugai, actress (d. 2018)
• March 16 – Hisako Tsuji, violinist (d. 2021)
• April 7 – Miyoko Asō, actress and voice actress (d. 2018)
• May 19 – Tadashi Sawashima, film and theater director (d. 2018)
• May 30 – Tsuneo Watanabe, businessman
• June 12 – Noriko Ibaragi, poet, playwright, essayist and translator (d. 2006)
• June 15 – Shigeru Kayano, Ainu activist (d. 2006)
• June 16 – Taketoshi Naito, actor (d. 2012)
• June 19 – Ōuchiyama Heikichi, sumo wrestler (d. 1985)
• June 28 – Mitsugi Ohno, glassblower (d. 1999)
• September 6 – Shinichi Hoshi, novelist and writer (d. 1997)
• September 15 – Shohei Imamura, film director (d. 2006)
• December 9
  • Michiyoshi Doi, film director (d. 1975)
  • Keiji Sada, actor (d. 1964)
• December 25 – Hitoshi Ueki, (d. 2007)

• January 28 – Katō Takaaki, politician and 24th Prime Minister of Japan (b. 1860)
• February 1 – Ishibashi Ningetsu, author and literature critic (b. 1865)
• February 14 – Enkichi Ōki, politician (b. 1871)
• March 9 – Mikao Usui, founder of Reiki (b. 1865)
• April 7
  • Ozaki Hōsai, poet (b. 1885)
  • Hozumi Nobushige, statesman and jurist (b. 1855)
• April 28 – Kawamura Kageaki, field marshal (b. 1850)
• June 28 – Hirai Seijirō, railroad engineer (b. 1856)
• July 4 – Ushinosuke Mori, anthropologist and folklorist (b. 1877)
• July 9 – Fujii Kōichi, admiral (b. 1858)
• July 23 – Fumiko Kaneko, anarchist (b. 1903)
• September 8 – Thomas Kurihara, actor and film director (b. 1885)
• September 11 – Matsunosuke Onoe, kabuki and silent film actor (b. 1875)
• September 28 – Satarō Fukiage, rapist and serial killer (b. 1889)
• November 28 – Takahira Kogorō, diplomat and ambassador (b. 1854)
• December 25 – Emperor Taishō, 123rd Emperor of Japan (b. 1879)^[1]

• List of Japanese films of the 1920s