Plant nutrition encompasses a vast array of inorganic and organic substances that plants obtain from external sources. Plants have specific requirements for two distinct types of nutrients: macro- and micronutrients. These essential elements include nitrogen (N), phosphorous (P), zinc (Zn), iron (Fe), boron (B), potassium (K), calcium (Ca), sulfur (S), and magnesium (Mg). These nutrients play pivotal roles in regulating biochemical processes, enhancing disease resistance, and ultimately influencing crop quality. Given the rapid global population growth and the concurrent decline in crop yields, food security has become a pressing concern. Therefore, it is imperative to apply nutrients in a balanced manner to optimize crop yield and ensure an ample food supply. Furthermore, nutrients significantly contribute to soil fertility, thereby augmenting its productivity for sustained plant growth. This chapter offers comprehensive insights into the types of macro- and micronutrients, their functions within plants, their mechanisms of uptake and mobilization, as well as the symptoms associated with their deficiencies.