1942 in Japan

• Emperor: Hirohito[1]
• Prime Minister: Hideki Tōjō

Below, events of World War II have the "WWII" preface

• 11 January – Japanese paratroopers land on Sulawesi.
• 12 January – Japan declares war on the Dutch.
• 22 January – Hideki Tōjō warns Australia that "if you continue resistance, we Japanese will destroy you."
• 4 February – Japan demands the surrender of Singapore.
• 17 February – Singapore is renamed Shōnan ("Light of the South").
• 20 March – The navy minister, Admiral Shigetarō Shimada says that in view of the Allies' "Retaliation and hatred", Japan would no longer follow recognized rules of sea warfare.
• 18 April – Doolittle Raid, the first bombing raid on the Japanese home islands
• 25 May – Four ships leave Hokkaido to stage a diversionary raid on the Aleutian Islands.
• 4–7 June – Battle of Midway
• 21 August – Battle of the Tenaru
• 11–12 October – Battle of Cape Esperance
• 12–15 November – Naval Battle of Guadalcanal

Junichiro Koizumi

• January 8 – Junichiro Koizumi, 56th Prime Minister of Japan
• January 27 – Tasuku Honjo, immunologist
• February 1 – Masa Saito, professional wrestler (d. 2018)
• March 29 – Kenichi Ogata, actor
• April 2 – Hiroyuki Sakai, chef
• April 25 – Katsuji Adachi, professional wrestler (d. 2010)
• May 24 – Ichirō Ozawa, politician
• July 3 – Mitsuhiro Kitta, golfer
• July 5 – Motoaki Inukai, footballer
• July 22 – Toyohiro Akiyama, astronaut
• August 31 – Isao Aoki, golfer
• September 16 – Tadamasa Goto, yakuza boss
• September 19 – Nobuo Sekine, sculptor (d. 2019)

• May 11 – Sakutarō Hagiwara, writer, poet and critic (b. 1886)
• May 29 – Akiko Yosano, author and poet (b. 1878)
• June 4 – Tamon Yamaguchi, admiral (b. 1892)
• June 5 – Ryusaku Yanagimoto, captain (b. 1894)
• August 21 – Kiyonao Ichiki[2] (b. 1892)
• August 26 – Junichi Sasai, aviator (b. 1918)
• September 5 – Toshinari Maeda, general (b. 1885)
• October 12 – Aritomo Gotō, admiral (b. 1888)
• October 21 – Toshio Ōta, aviator (b. 1919)
• October 26 – Yumio Nasu, major general (b. 1892)
• November 5 – Kiyoura Keigo, politician and Prime Minister of Japan (b. 1850)
• November 23 – Tomitarō Horii, lieutenant general (b. 1890)
• December 4 – Atsushi Nakajima, author (b. 1909)

• List of Japanese films of the 1940s