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).
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.
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.