Prince Yasuhiko Asaka (朝香宮鳩彦王 Asaka-no-miya Yasuhiko-ō) (2 October 1887 - 12 April 1981) was commander of Japanese forces in the final assault on Nanjing, during the Second Sino-Japanese War. He was a member of the Japanese Imperial family and uncle-in-law to Emperor Hirohito.
In November 1937, Prince Asaka was appointed commander of a section of the Japanese forces then descending on Nanjing, falling under the command of commander-in-chief General Matsui Iwane. On 5 December Asaka reportedly issued a secret order to "kill all captives."  Although, the attack was ordered by General Matsui, Asaka took on temporary command, as the General was suffering from tuberculosis. Even after Matsui eventually entered Nanjing on 17 December, 4 days after the fall, he did nothing to stop the carnage.
Although he served on Japan's wartime Supreme War Council until 1945, and was interrogated after the war about his role in the Nanjing massacre, he was never bought to trial. This was as a result of General Douglas MacArthur's decision to grant immunity to all members of the Imperial family. However, Asaka was stripped of his Imperial status and privileges in 1947.
As common citizens, Yasuhiko's family moved to Atami, Shizuoka Prefecture, Japan. He converted to Roman Catholicism, making him the first Imperial family member to do so. In the 1950s, he spent most of his time playing golf and developing golf courses. Yasuhiko Asaka died on 12 April 1981, of natural causes.