Potassium (K + ) is an essential mineral macronutrient abundantly present in the cytosol which, unlike other macronutrients, is not metabolized and does not integrate into macromolecules. Compared to animal cells, K +  is more abundantly present in plant cells.  Overall performance of the plant, and operation of metabolic machinery depends upon intracellular K + homeostasis (K + uptake and efflux) via K + channels and transporters acting as mediators of cellular responses during plant development. Unlike animals, plants lack sodium/K + exchangers; plant cells have developed unique transport systems for K + accumulation and release. In Arabidopsis thaliana, 71 K + channels and transporters have been identified and categorized into six families.  Plant adaptive responses to several abiotic and biotic stresses are mediated by regulation of intracellular K + homeostasis. In this report, we highlight the role of K + in abiotic and biotic stresses, features of channels and transporters responsible for its homeostasis along with its evolutionary relationship, perception and sensing mechanisms, and K + deficiency triggering different signaling cascades.  Overall, this book covers the role of K + in plants would be significantly helpful to research, academic community as well as students to understand the one of the major attributes of plant biology.