Ibaraki, prefecture (1990 pop. 2,845,411), 2,352 sq mi (6,092 sq km), central Honshu, Japan. Mito is the capital. The prefecture yields tobacco, cereals, coal, copper, petrochemicals, and electric machinery. A nuclear fuel plant in Tokaimura, N central Ibaraki, was the site of accident involving an uncontrolled chain reaction in 1999.

Ibaraki may refer to any of the following places in Japan:

• Ibaraki Prefecture, one of the 47 prefectures of Japan
• Ibaraki, Ibaraki, a town in Ibaraki Prefecture
• Ibaraki, Osaka, a city in Osaka Prefecture