Wheat (Triticum aestivum L.) is one of the world's three staple crops and accounts for approximately 20% of the total calories consumed by the world's population. It is known that wheat is a difficult crop to introduce foreign genes into, having a large genome (16 Gb) containing three highly related subgenomes (AABBDD). Owing to the low transformation efficiency of wheat, it is difficult to apply new technologies such as genome editing and basic research based on molecular biology, such as the discovery of useful genes and functional analysis. Recently, the completion of a wheat genome map by the International Wheat Genome Sequencing Consortium (IWGSC) and the development of a stable and reproducible wheat transformation system have accelerated research regarding the expression and control of useful genes. In this review, we introduce in detail the recently developed highly efficient Agrobacterium-mediated wheat transformation system and its applications in plant biotechnology, such as RNA interference (RNAi), overexpression, and gene editing using this system.