Omusubi (おむすび) is a traditional Japanese rice ball snack or meal that is typically made by shaping steamed rice into a compact ball or triangle shape with the hands. The rice can be plain or mixed with various ingredients such as salt, furikake (a Japanese seasoning), sesame seeds, and other fillings like grilled fish, pickled plum, cooked vegetables or meat, and more.

Omusubi is a popular portable food item in Japan, often eaten as a quick breakfast or lunch or taken on picnics or as a snack on-the-go. It is usually wrapped in nori (dried seaweed) to help hold its shape and to add flavor and nutrition.

Omusubi is also known as onigiri, which literally means "rice ball" in Japanese. The term "onigiri" is more commonly used in some regions of Japan, while "omusubi" is used in others. Regardless of the name, the dish is a simple, yet satisfying meal that has been enjoyed by the Japanese for centuries.