Tosya (Ottoman Turkish: طوسيه) is a town and district of Kastamonu Province in the Black Sea region of Turkey. According to the 2000 census, the population of the district is 41,995. About 30,000 live in the town of Tosya. The district covers an area of 1,186 km² (458 sq mi), and the town lies at an elevation of 1,231 m (4,039 ft). The district produces a third of Turkey's total rice harvest.