Over the past decade, the role of the 14–3-3 protein has received increasing interest. Seven subtypes of 14–3-3 proteins exhibit high homology; however, each subtype maintains its specificity. The 14–3-3ε protein is involved in various physiological processes, including signal transduction, cell proliferation, apoptosis, autophagy, cell cycle regulation, repolarization of cardiac action, cardiac development, intracellular electrolyte homeostasis, neurodevelopment, and innate immunity. It also plays a significant role in the development and progression of various diseases, such as cardiovascular diseases, inflammatory diseases, neurodegenerative disorders, and cancer. These immense and various involvements of 14–3-3ε in diverse processes makes it a promising target for drug development. Although extensive research has been conducted on 14–3-3 dimers, studies on 14–3-3 monomers are limited. This review aimed to provide an overview of recent reports on the molecular mechanisms involved in the regulation of binding partners by 14–3-3ε, focusing on issues that could help advance the frontiers of this field.