Cotton (Gossypium hirsutum L.) is the world's most susceptible agronomic crop to various biotic and abiotic stresses. Potassium (K) is the well-known plant nutrient that enhances stress tolerance of plants. This monograph reports K-induced stress tolerance of cotton genotypes and the positive impacts of adequate K nutrition on their growth, yield and K uptake. Adequate K nutrition increased the growth and yield of cotton genotypes by enhancing their resistance against diseases and insect pest infestations. These results advocate that adequate K nutrition can effectively promote low-pesticide-input, environment-friendly sustainable cotton production.