<p>Oral Lichen Planus (OLP) is a chronic inflammatory disorder of the oral mucosa characterized by diverse clinical manifestations and an uncertain aetiology. Emerging evidence suggests a critical role for mast cells in the pathogenesis and progression of OLP. This systematic review and meta-analysis investigated the involvement of mast cells in OLP, with a focus on their contribution to disease chronicity and severity. A comprehensive literature search (up to September 2024) identified 34 studies for qualitative synthesis and 14 for quantitative analysis. Risk of bias was assessed using the modified Newcastle–Ottawa Scale, and data were analyzed using Review Manager 5.4. Mast cell density was significantly higher in OLP tissues compared to controls, particularly in erosive and atrophic subtypes. Mast cells were commonly located near blood vessels and inflammatory infiltrates, contributing to a pro-inflammatory microenvironment and tissue remodelling. Notably, increased mast cell degranulation was observed, further amplifying the inflammatory response. Meta-analysis confirmed that elevated mast cell degranulation is significantly associated with progression to erosive OLP. The mounting evidence highlights the central role of mast cells in the pathogenesis, chronic inflammation, and clinical advancement of OLP.</p>