Salinity is one of the major constraints to plant growth and development across the globe that leads to the huge crop productivity loss. Salinity stress causes impairment in plant's metabolic and cellular processes including disruption in ionic homeostasis due to excess of sodium (Na+) ion influx and potassium (K+) efflux. This condition subsequently results in a significant reduction of the cytosolic K+ levels, eventually inhibiting plant growth attributes. K+ plays a crucial role in alleviating salinity stress by recasting key processes of plants. In addition, K+ acquisition and retention also serve as the perquisite trait to establish salt tolerant mechanism. In addition, an intricate network of genes and their regulatory elements are involved in coordinating salinity stress responses. Furthermore, plant growth regulators (PGRs) and other signalling molecules influence K+-mediated salinity tolerance in plants. Recently, nanoparticles (NPs) have also been found several implications in plants with respect to their roles in mediating K+ homoeostasis during salinity stress in plants. The present review describes salinity-induced adversities in plants and role of K+ in mitigating salinity-induced damages. The review also highlights the efficacy of PGRs and other signalling molecules in regulating K+ mediated salinity tolerance along with nano-technological perspective for improving K+ mediated salinity tolerance in plants.