<p><i>Thymus capitatus</i>, a Mediterranean aromatic species of the Lamiaceae family, produces an essential oil (EO) characterized by high levels of monoterpenic phenols, mainly carvacrol and thymol, which are widely recognized for their strong antimicrobial and antifungal properties. This review critically examines current knowledge on the chemical variability and antifungal potential of <i>T. capitatus</i> EO, with particular emphasis on its relevance to grapevine trunk diseases (GTDs). The EO has been extensively studied <i>in vitro</i> against a broad range of human and plant pathogenic fungi, including wood-inhabiting species associated with GTDs. However, its practical application in viticulture remains largely limited to laboratory and preliminary experimental studies, with scarce data available under <i>in planta</i> or vineyard conditions. Potential applications include pruning-wound protection and trunk delivery systems, but several constraints still need to be addressed, including chemical variability linked to geographical and environmental factors, formulation stability, compound persistence in woody tissues, phytotoxicity risks, and ecological impacts on vine-associated microbiota. This review synthesizes and discusses the phytochemical variability, antifungal activity, and mechanisms of action of <i>T. capitatus</i> EO, while highlighting current limitations, knowledge gaps, and future research priorities required to support its potential integration into sustainable GTD management strategies.</p> Graphical Abstract <p></p>