Fungi in the genus occur in every environment in both terrestrial and marine contexts, where they have been quite frequently found in association with plants and animals. The relationships of symbiotic fungi with their hosts are often mediated by bioactive secondary metabolites, and species represent a prolific source of these compounds. This review highlights the biosynthetic potential of marine-derived strains, using accounts from the literature published since 2016. Over 500 secondary metabolites were extracted from axenic cultures of these isolates and about 45% of them were identified as new products, representing a various assortment of chemical classes such as alkaloids, meroterpenoids, isocoumarins, anthraquinones, xanthones, phenalenones, benzofurans, azaphilones, and other polyketides. This impressive chemodiversity and the broad range of biological properties that have been disclosed in preliminary assays qualify these fungi as a valuable source of products to be exploited for manifold biotechnological applications.