Hoi (宝飯郡, Hoi-gun) was a district located in eastern Aichi Prefecture, Japan.
Originally covering all of eastern Mikawa, Shitara District to the north was separated from Hoi in 903.
In the cadastral reforms of the early Meiji period, on July 22, 1878 modern Hoi District was created, with its headquarters at Goyu-shuku, a former station on the Tōkaidō.
With the organization of municipalities on October 1, 1889, Hoi District was divided into 33 villages.
When the town of Kozakai was merged into Toyokawa on February 1, 2010, Hoi ceased to exist as an administrative division.