Events from the year 1884 in Japan.
- November - Chichibu Incident
- Unknown date – Yamada Electronic Wire Manufacturing, as predecessor of Furukawa Electronic Work has founded.[page needed]
- January 1 - Chikuhei Nakajima (d. 1949), naval officer, engineer, and politician, founded Nakajima Aircraft Company
- January 4 - Gyosaku Morozumi, (d. 1963), general in the Imperial Japanese Army
- January 14 - Tetsuzan Nagata, (d. 1935), general in the Imperial Japanese Army
- February 22 - Tamaki Miura (d. 1946), operatic soprano
- April 4 - Isoroku Yamamoto (d. 1943), Marshal Admiral of the Navy and the commander-in-chief of the Combined Fleet during World War II
- December 30 - Hideki Tojo (d. 1948), leader of the Imperial Rule Assistance Association and the 40th Prime Minister of Japan