The chapter discusses the origin, dispersal, cultivation, and variation of rice. The genus *Oryza* includes two cultivated species, *O. sativa* (Asian cultivated rice) and *O. glaberrima* (African cultivated rice), with the former being more widely distributed globally. The genus likely originated in Gondwanaland about 130 million years ago and spread to different continents as Gondwanaland broke up. *O. sativa* is believed to have domesticated from *O. rufipogon* and *O. nivara*, while *O. glaberrima* may have domesticated from *O. longistaminata*, *O. breviligulata*, and *O. glaberrima* in the Niger River delta. *O. sativa* varieties are classified into six groups based on genetic affinity, with indica rices corresponding to group I and japonicas to group VI. Indica rices were likely domesticated in the foothills of the Himalayas, while japonicas were domesticated in South China. Indicas spread throughout the tropics and subtropics, while japonicas moved northward to become temperate ecotypes and southward to Southeast Asia, West Africa, and Brazil to become tropical ecotypes. Rice is now cultivated between 55°N and 36°S latitudes under various conditions, and human selection and adaptation have led to numerous cultivars. The International Rice Research Institute (IRRI) has played a crucial role in varietal improvement, leading to the development of high-yielding varieties that account for 70% of global rice cultivation. Rice production doubled between 1966 and 1990 due to these improvements, and it must increase by 60% by 2025 to meet growing demand. New tools in molecular and cellular biology, such as anther culture, molecular marker-assisted selection, and genetic engineering, will continue to enhance rice improvement.The chapter discusses the origin, dispersal, cultivation, and variation of rice. The genus *Oryza* includes two cultivated species, *O. sativa* (Asian cultivated rice) and *O. glaberrima* (African cultivated rice), with the former being more widely distributed globally. The genus likely originated in Gondwanaland about 130 million years ago and spread to different continents as Gondwanaland broke up. *O. sativa* is believed to have domesticated from *O. rufipogon* and *O. nivara*, while *O. glaberrima* may have domesticated from *O. longistaminata*, *O. breviligulata*, and *O. glaberrima* in the Niger River delta. *O. sativa* varieties are classified into six groups based on genetic affinity, with indica rices corresponding to group I and japonicas to group VI. Indica rices were likely domesticated in the foothills of the Himalayas, while japonicas were domesticated in South China. Indicas spread throughout the tropics and subtropics, while japonicas moved northward to become temperate ecotypes and southward to Southeast Asia, West Africa, and Brazil to become tropical ecotypes. Rice is now cultivated between 55°N and 36°S latitudes under various conditions, and human selection and adaptation have led to numerous cultivars. The International Rice Research Institute (IRRI) has played a crucial role in varietal improvement, leading to the development of high-yielding varieties that account for 70% of global rice cultivation. Rice production doubled between 1966 and 1990 due to these improvements, and it must increase by 60% by 2025 to meet growing demand. New tools in molecular and cellular biology, such as anther culture, molecular marker-assisted selection, and genetic engineering, will continue to enhance rice improvement.