Speed breeding is a suite of techniques that involves the manipulation of environmental conditions under which crop genotypes are grown, aiming to accelerate flowering and seed set, to advance to the next breeding generation as quickly as possible. The speed breeding concept was inspired by NASA’s efforts to grow crops in space, using an enclosed chamber and an extended photoperiod. Through speed breeding the creation of inbred plant cultivars can be accelerated and all current methods of plant research including the development of biparental and more complex mapping populations, pyramiding traits, hastening backcrosses, phenotyping adult plant traits, mutant studies, and genetic transformation experiments can be seamlessly integrated. Till date speed breeding has been applied for many agricultural and horticultural crops, an account of which is also briefed in this chapter. Just like any other breeding technology, speed breeding has its limitations and should only be applied to those aspects of a breeding or research program that stand to gain from rapid generation advancement. This chapter provides insight into principle behind speed breeding, as well as its application in crop improvement, benefits, and drawbacks.