Mast cells play a crucial role in the immune response, particularly in allergic reactions and inflammatory processes. In the context of oral diseases, mast cells have been implicated in various pathological conditions, including gingivitis, periodontitis, oral lichen planus, and oral cancer. This comprehensive review aims to explore the role of mast cells in the pathogenesis of these oral diseases, focusing on their activation, degranulation, and subsequent release of mediators such as histamine, cytokines, and growth factors. Furthermore, this review discusses the interaction between mast cells and other immune cells, as well as their involvement in angiogenesis, tissue remodelling, and pain modulation in the oral cavity. A thorough understanding of the role of mast cells in oral diseases may pave the way for the development of novel therapeutic strategies targeting mast cell activation and function, ultimately improving the management of these conditions.