<p>The growing environmental footprint of conventional textile coatings has intensified the search for sustainable and biodegradable alternatives. Solvent-based finishing systems, persistent functional chemicals, and emission-intensive processing routes contribute to volatile organic compound emissions, wastewater ecotoxicity, microplastic release, and barriers to textile circularity. In particular, the extensive use of per- and polyfluoroalkyl substances in textile finishes has raised serious concerns due to their environmental persistence and adverse health effects. In parallel, biodegradable nonwoven textiles, especially those based on polylactic acid, have attracted increasing attention for medical, hygiene, and disposable applications owing to their bio-based origin, compostability, and industrial relevance. This review evaluates advances in biopolymer-based bio-nanocomposite coatings for biodegradable nonwoven textiles, with emphasis on water-based systems, bio-derived polymer matrices, and environmentally benign functional additives. Sustainability aspects related to material selection, processing routes, biodegradability, end-of-life scenarios, and circular economy compatibility are discussed, highlighting current challenges and future opportunities for responsible textile coating technologies.</p>