Tef [Eragrostis tef (Zucc.) Trotter] is an important cereal crop in the Horn of Africa, particularly in Ethiopia, where it is annually cultivated on over three million hectares of land. This gluten-free and highly nutritious grain is staple food for more than seventy million people in Ethiopia and plays a vital role in addressing food security in the country. Tef is proven for its adaptability to different agroecologies and resilience to drought and marginal environments, making it an essential crop for sustainable agriculture in the face of climate change. Despite its resilience to diverse environmental stresses, the productivity of tef is severely affected by lodging and extreme drought prevailing in the country. Efforts have been made in the past to develop high-yielding, drought-tolerant, and lodging-tolerant tef varieties. The recent advancement in omics facilitates the identification of key traits useful in climate change adaptation, nutritional values, and farmers’ preferences. Furthermore, gluten-free nature together with high nutrition content and value-added products have increased interest in the global market of this crop. This chapter aims to provide an updated comprehensive overview of the origin, domestication, production status, agronomy, and breeding of the tef crop. In line with the present day frontline “mantra” issues, the review also emphasizes highlighting climate change resilience and adaptation and nutrition and contribution to nutrition security aspects of the tef crop. Furthermore, it gives brief accounts of the advance concerning the “omics” and value-addition pertaining to the tef crop. In general, this chapter on tef as part of the general compilation as a book on millets is presumed to provide an up-to-date abridged synthesis of the existing information on the diverse aspects of the crop useful for the academia, researchers, and policymakers and other interested readers.