Uonuma Koshihikari Diamond Selection is a Japanese short-grain Koshihikari rice grown by the Green Earth Tsunan agricultural cooperative in Tsunan, in the Uonuma region of Niigata Prefecture. The name Diamond Selection refers to the Diamond Award, which the cooperative received after winning five consecutive gold awards at the Rice Taste Analysis and Appraisal Contest.

The paddies are irrigated with snowmelt. The cooperative prepares the soil with compost and other organic materials and applies natural, mineral-rich amendments at different stages of plant growth.

Once cooked, the rice has a mild sweetness and a sticky texture. It can be served plain, paired with grilled fish, or shaped into onigiri, Japanese rice balls.