[Excerpt] The textile industry, although essential to Europe’s economy, exerts a substantial environmental impact due to intensive resource consumption and highly polluting dyeing and finishing processes. Conventional petrochemical dyes rely on hazardous, water-demanding methods that generate toxic effluents, reinforcing the need for safer and renewable alternatives. Natural dyes offer a promising sustainable route, as they are biodegradable, less toxic, and can provide a wide range of functionalities, despite challenges such as limited fiber affinity and uneven coloration. Marine algae, macro and microalgae, are rich in biopolymers, pigments and bioactive molecules. Ulvan, a sulfated polysaccharide from Ulva, has attracted increasing interest as a sustainable auxiliary in textile dyeing and finishing processes. Hence, this study evaluates eco-friendly ulvan extraction methods (citric acid, ultrasound, enzymatic and combined processes) from Ulva macroalgae, while simultaneously exploring the potential of microalgae as a source of pigments and bioactive compounds to enable sustainable algae-based dyeing and functionalization of textiles. The findings highlight the strong potential of algae derived formulations as scalable and sustainable alternatives for the textile sector.