True slime molds (Eumycetozoa) represent a monophyletic clade within the phylum Amoebozoa, comprising the lineages Myxogastria, Dictyostelia, and Protosporangiida. Although historically misclassified as fungi, recent molecular and biochemical studies underscore their distinct evolutionary trajectories and rich metabolomic profiles. In this review, we synthesize current knowledge on Eumycetozoa as a reservoir of bioactive compounds, detailing how secondary metabolites-including polysaccharides, amino acids, unsaturated fatty acids, terpenoids, and glycosides-vary across plasmodia, fruiting bodies, and spores. A systematic literature search in major scientific databases accounted for legacy nomenclature and leveraged chemoinformatic tools for compound verification. Our findings reveal 298 distinct metabolites that serve ecological roles in nutrient recycling and interspecies interactions, while also showing promise for controlling agricultural pests and pathogens. Notably, certain glycosides, lectins, and polyketides exhibit antimicrobial or cytotoxic activities, indicating their potential utility in managing these biological challenges. By consolidating current data and emphasizing the wide taxonomic range of Eumycetozoa, this review highlights the critical need for comprehensive biochemical and genomic investigations. Such efforts will not only advance our understanding of slime mold metabolomes and their evolutionary significance but also pave the way for innovative, eco-friendly applications.