The mineral element silicon, accumulated in the leaves and roots of various plants, plays a crucial role in increasing resistance to various biotic and abiotic stresses. Although considered a mineral element that is not essential for plant life, silicon provides significant benefits. This mineral accumulated in tissues provides increased resistance of cells to mechanical stresses, reduced water loss through transpiration, increased resistance to sunlight, and reduced metal toxicity and salt stresses. Plants accumulate silicon differently, depending on their root type and functionality. Molecular studies have made it possible to identify the genes responsible for silicon accumulation. In the future, advances in this field could improve techniques for studying the mechanisms involved in silicon uptake, not only by increasing its availability within tissues but also by improving its storage capacity. Unfortunately, many plants cannot absorb silicon and, therefore, cannot benefit from the mechanisms that lead to increased resistance to various biotic and abiotic stresses. This review aims to highlight the benefits obtainable with the use of silicon in those plants capable of absorbing it, particularly in the control of biotic and abiotic stresses.