<p>Bitter vetch (<i>Vicia ervilia</i> (L.) Willd.) is one of the earliest domesticated crops, as evidenced by ancient texts and archaeobotanical remains. Following its domestication in the Near East and subsequent spread across the Mediterranean region, it became an important feed source for ruminants and poultry due to its high protein content. However, the presence of antinutritional factors led to its gradual replacement by other crops. Today, bitter vetch is considered an underutilized legume with significant potential for sustainable agriculture, owing to its adaptability to marginal environments and low input requirements. Recent research has demonstrated its functional and physicochemical properties, highlighting its potential for application as an ingredient in the food and medical industries. In this context, traditional knowledge is increasingly being integrated into modern processing systems. Furthermore, substantial genetic and phenotypic diversity has been identified both among and within landraces, along with notable tolerance to a range of biotic and abiotic stresses, offering valuable opportunities for future breeding programs. This review summarizes current knowledge on bitter vetch, including advances in archaeobotanical research, genetic diversity, stress tolerance, breeding efforts, and interactions with other organisms (e.g. symbiotic microorganisms and insects). It also examines its potential applications in feed, food, packaging, and medical sectors. Limitations and research gaps in key scientific areas, such as archaeobotany, diversity exploitation and record, and biomaterials applications, are discussed to support future research and promote its wider utilization.</p>