Barley is a resilient crop plant with higher tolerance than other cereal plants for several types of abiotic stress. In this chapter, we describe the genetic components underlying barley’s response to abiotic stresses, including soil acidity, boron toxicity, soil salinity, drought, temperature, and nutrient deficiency. We describe typical symptoms observed in barley in response to these stresses. We enumerate the major qualitative trait loci (QTLs) identified so far, such as FR-H1 and FR-H2 for low-temperature tolerance. We also discuss candidate genes that are the basis for stress tolerance, such as HVP10, which underlies the HvNax3 locus for salinity tolerance. Although knowledge about barley’s responses to abiotic stresses is far from complete, the genetic diversity in cultivated barley and its close wild relatives could be further exploited to improve stress tolerance. To this end, the release of the barley high-quality reference genome provides a powerful tool to facilitate identification of new genes underlying barley’s relatively high tolerance to several abiotic stresses.