Hideo Yokoyama (横山 秀夫, Yokoyama Hideo, born 1957) is a Japanese novelist.

Yokoyama specializes in mystery novels.

He repeated his Kono Mystery ga Sugoi! No. 1 ranking in 2013 with Six Four (64).

The English edition of Six Four, translated by Jonathan Lloyd-Davies, was shortlisted for the 2016 CWA International Dagger.^[1]

He is known for his career as journalist for the Jomo Shimbun, the regional paper in Gunma.

• Six Four (original title: 64 Rokuyon), trans. Jonathan Lloyd-Davies (riverrun, 2016)
• Seventeen (original title: Kuraimāzu hai [Climber's High]), trans. Louise Heal Kawai (riverrun, 2018)
• Prefecture D (original title: Kage no Kisetsu), trans. Jonathan Lloyd-Davies (riverrun, 2019)

• Motive (original title: Dōki), trans. Beth Cary (Ellery Queen's Mystery Magazine, May 2008)

• My Favourite Mystery, "Paradise lost in the box" by Kenji Takemoto (Mystery Writers of Japan, Inc. [1])

Japanese Awards

• 1998 – Matsumoto Seicho Prize: "Kage no Kisetsu" (Season of Shadows)
• 2000 – Mystery Writers of Japan Award for Best Short Story: "Motive"
• 2003 – The Best Japanese Crime Fiction of the Year (Kono Mystery ga Sugoi! 2003): Han'ochi (Half a Confession)
• 2005 – Nominee for Honkaku Mystery Award for Best Fiction: Rinjō (Initial Response ^[2])
• 2013 – The Best Japanese Crime Fiction of the Year (Kono Mystery ga Sugoi! 2013): Six Four

UK Award

• 2016 – Shortlisted for the CWA International Dagger: Six Four^[1]

• Deguchi no Nai Umi (出口のない海), 1996
• Kage no Kisetsu (陰の季節), 1998
  • English translation: Prefecture D, riverrun, 2019
• Han'ochi (半落ち), 2002
• Kuraimāzu hai (Climber's High) (クライマーズ・ハイ), 2003
  • English translation: Seventeen, riverrun, 2018
• Rupan no Shōsoku (ルパンの消息), 2005
• Shindo Zero (震度0), 2005
• Rokuyon (64), 2012
  • English translation: Six Four, riverrun, 2016
• Nōsu Raito (North Light) (ノースライト), 2019
  • English translation: North Light, riverrun, 2024

• Dōki (動機), 2000
• Kao (顔), 2002
• Fukaoi (深追い), 2002
• Shinsō (真相), 2003
• Kagefumi (影踏み), 2003
• Kanshugan (看守眼), 2004
• Rinjō (臨場), 2004
• Rinjō Special Book (臨場スペシャルブック), 2010

• Half a Confession (2004) (Han'ochi)
• Deguchi no Nai Umi (2006)
• Climber's High (2008) (Kuraimāzu hai)
• Rinjō (2012)
• Rokuyon (64) Part I (2016)
• Rokuyon (64) Part II (2016)
• Kagefumi (2019)

• Doki (translated into Mandarin Chinese) – Google Books