Soil salinity is a serious environmental challenge that greatly limits the global agricultural output as well as environmental sustainability. Plant growth and productivity depend mainly on soil physicochemical and biological attributes, which are significantly altered in highly saline soils. Excessive levels of soil salts, such as sodium, are highly detrimental to plants and disrupt physiological and cellular homeostasis in multifarious ways. An excess of Na- ions frequently disrupts osmotic balance, triggers ionic imbalance, impairs nutrient and water uptake, and promotes oxidative stress, leading to subsequent cellular damage. Such an increase in soil salinity is often detected by specialized receptors localized in root membranes, which transduce signals regulated by a wide array of genes. Thus, salinity stress responses and tolerance are multigenic traits. Moreover, plants employ several tolerance mechanisms, such as osmoprotectant accumulation, upregulation of antioxidant defense mechanisms, diverse signalling pathways (SOS and MAPK pathways), and phytohormone signalling, to adapt and tolerate salinity stress. This review consolidates the current understanding of salt stress detection, signal transduction, ion transport pathways, adaptive responses, salt-responsive genes, and mitigation techniques employed to develop salt-tolerant crop cultivars.