The optimum growth and development of plants depend on some basic components obtained from nature. These include water, carbon dioxide, light, and mineral elements. In addition to these essential elements, certain elements known as beneficial elements support the growth of plants. Finally, some elements are required in trace and ultratrace quantities. These elements include selenium, silicon, manganese boron, cobalt, molybdenum, nickel, aluminum, copper, iodine, iron, and zinc. Selenium is a component of several important enzymes like glutathione peroxidases, thioredoxin reductase, and iodothyronine deiondinase. Silica is required by plants of the Poaceae family to gain strength, and it is essential for lodging resistance in rice plants. Nickel is also a constituent of enzymes such as urease, glyoxalase I, superoxide dismutase, [NiFe]-hydrogenase, carbon monoxide dehydrogenase, and acetyl-coenzyme A. Molybdenum is also an important component of enzyme nitrate reductase. Nickel helps the plant to metabolize urea nitrogen into a bioavailable form, that is ammonia, which leads to improved plant growth. The elements like zinc and copper are essentially required by plants in small amounts. The essential elements play important roles in various processes, such as growth hormone production, internode elongation, and various enzymatic activities. The research on beneficial elements has proven their roles in plant growth and development. In addition, an optimum supply of such beneficial and ultratrace elements helps them tackle abiotic and biotic stresses. For example, silica and selenium supplementation have been found to impart arsenic stress tolerance to rice plants. The studies point to the fact that even if the essentiality of some elements is not proved, they do perform crucial roles in plants. This chapter discusses the importance of essential, beneficial, and ultratrace elements in plant growth, development, and stress tolerance.