The review focuses on the analysis of new information concerning the role of phytohormones in the regulation of dormancy and seed germination. It is noted that abscisic acid (ABA) and gibberellins (GA) belong to key endogenous factors, which determine the state of seeds. High endogenous ABA and low GA levels result in deep seed dormancy, while low ABA and high GA levels induce the beginning of germination. Changes in accumulation of key hormones and expression of key regulators during seed maturation and germination were discussed. In addition to ABA and GA all other phytohormones are also involved in modulation of seed dormancy and germination, including auxin, cytokinins, ethylene, brassinosteroids, jasmonic acid, salicylic acid, and strigolactones. The two major aspects of the ABA/GA balance regulation—the balance of hormone levels and the balance of the signaling cascades were analyzed. The accumulation of plant hormones can positively or adversely affect seed germination, while interacting with each other. While the activity of plant hormones is controlled by the expression of genes at different levels, there are plant genes that activated in the presence of specific plant hormones. We presented the scheme of auxin, cytokinins, ethylene, brassinosteroids, jasmonic acid, salicylic acid, and strigolactones involvement into regulation of seed germination processes through an integrated network of interaction with ABA and gibberellins. The influence of external factors on the hormonal system during germination of seeds and the participation of phytohormones in the formation of protective reactions for the effects of abiotic stresses are discussed. The state of the study of the role of the phytohormonal system in the regulation of germination processes of cereal grains was characterized. The possibilities and perspectives of the use of exogenous phytohormones for presowing priming of seeds are analyzed in order to regulate the intensity of physiological and metabolic processes and increase the stress resistance.