Sorghum is a staple food crop for millions of the poorest and most food-insecure people in the semi-arid tropics, and ensuring its diversity and conservation is therefore important for global food and nutritional security. This chapter discusses the taxonomy of sorghum, in situ and ex situ germplasm conservation and diversity, the factors shaping sorghum diversity, geographical distribution of sorghum germplasm, germplasm gap analysis, and the use of cultivated and wild genepool of sorghum to enhance crop yields and broaden the genetic base of sorghum cultivars.