1966 in Japan

Incumbents

• Emperor: Hirohito
• Prime Minister: Eisaku Satō
• Chief Cabinet Secretary: Tomisaburo Hashimoto until August 1, Kiichi Aichi until December 3, Kenji Fukunaga
• Chief Justice of the Supreme Court: Kisaburo Yokota until August 5, Masatoshi Yokota from August 6
• President of the House of Representatives: Kikuchirō Yamaguchi until December 3, Kentarō Ayabe until December 26
• President of the House of Councillors: Yūzō Shigemune

  Events

• January 9 - The Kanai Building fire in Kawasaki City, Kanagawa Prefecture leaves 12 dead, 14 injured.
• February 4 -All Nippon Airways Flight 60 crashes into Tokyo Bay, killing all 133 people on board.
• March 4 - Canadian Pacific Air Lines Flight 402 crashes while landing at night with poor visibility at Tokyo International Airport, with 64 out of 72 on board killed.
• March 5 - BOAC Flight 911 crashes while encountering severe Clear-air turbulence over Mount Fuji shortly after taking off from Tokyo International Airport, killing all 124 on board.
• March 11 - A spa hotel caught fire in Minakami, Gunma Prefecture, 30 persons were lost to lives, 29 persons were hurt, according to Japan Fire and Disaster Management Agency official confirmed report.
• March 25 – Hachinohe Rinkai Line was opened.
• April 1 - Japan switches to the Metric system.
• April 26 - Japan's biggest postwar public transportation strike.
• August 22 - Frontier Tea Product Manufacturing, as predecessor of Ito En founded in Shizuoka City.
• September 25 - Two typhoons Helen and Ida landed in Japan on same days, according to Japanese government official confirmed report, total 317 persons were human fatalities with 824 persons were hurt.
• November 11 - All Nippon Airways Flight 533 crashes into the Seto Inland Sea, killing all 50 on board.

  Births

• January 5 - Yuri Amano, voice actress
• January 17 - George Morikawa, author and illustrator
• January 28 - Seiji Mizushima, anime director
• February 4 - Kyōko Koizumi, actress and singer
• March 7 - Atsushi Sakurai, singer
• April 3 - Mina Tominaga, voice actress
• April 19 - El Samurai, professional wrestler
• April 27 - Yoshihiro Togashi, author and illustrator
• June 26 - Yūko Minaguchi, voice actress
• July 25 - Wataru Takagi, voice actor
• July 28 - Shikao Suga, singer
• August 4 - Kensuke Sasaki, professional wrestler
• September 11 - Kiko, Princess Akishino, wife of Fumihito, Prince Akishino
• September 12 - Princess Akishino
• October 31 - Koji Kanemoto, professional wrestler
• November 2 - Yoshinari Ogawa, professional wrestler
• November 6 - Kae Araki, voice actress
• November 28 - Narumi Yasuda, actress
• December 12 - Último Dragón, professional wrestler

  Deaths

• March 6 - Michitaro Totsuka, admiral
• July 12 - D.T. Suzuki, philosopher
• November 9 - Jisaburō Ozawa, admiral
• November 14 - Zengo Yoshida, admiral