Before and during World War II, the Empire of Japan committed numerous war crimes and crimes against humanity across various Asian–Pacific nations, notably during the Second Sino-Japanese War and the Pacific War. These incidents have been referred to as "the Asian Holocaust" and "Japan's Holocaust", and also as the "Rape of Asia". The crimes occurred during the early part of the Shōwa era.
The Imperial Japanese Army (IJA) and the Imperial Japanese Navy (IJN) were responsible for war crimes leading to millions of deaths, ranging from sexual slavery and massacres to human experimentation, torture, starvation, and forced labor. Evidence of these crimes, including oral testimonies and written records such as diaries and war journals, has been provided by Japanese veterans.