Aichi Prefecture (愛知県, Aichi-ken^?) is a prefecture of Japan located in the Chūbu region. The region of Aichi is also known as the Tōkai region. The capital is Nagoya. It is the focus of the Chūkyō Metropolitan Area.

Originally, the region was divided into the two provinces of Owari and Mikawa. After the Meiji Restoration, Owari and Mikawa were united into a single entity. In 1871, after the abolition of the han system, Owari, with the exception of the Chita Peninsula, was established as Nagoya Prefecture, while Mikawa combined with the Chita Peninsula and formed Nukata Prefecture. Nagoya Prefecture was renamed to Aichi Prefecture in April 1872, and was united with Nukata Prefecture on November 27 of the same year.

The government of Aichi Prefecture is located in the Aichi Prefectural Government Office in Nagoya, which is the old capital of Owari.

The Expo 2005 World Exposition was held in Seto and Nagakute.

In the third volume of the Man'yōshū there is a poem by Takechi Kurohito 'The cry of the crane, calling to Sakurada; it sounds like the tide, draining from Ayuchi flats, hearing the crane cry'. Ayuchi is the original form of the name Aichi, and the Fujimae tidal flat is all that remains of the earlier Ayuchi-gata. It is now a protected area.