Arthrospira (Spirulina) platensis has attracted growing interest due to its ability to produce bioactive compounds such as polyphenols. However, their profitable recovery is currently a hot investigation topic, which has been remained a challenge due to the inherent limitations of various conventional extraction methods. The aim of this study was to select the most suitable extraction method to recover phenolic compounds and antiradical power (ARP) from A. platensis biomass. For this purpose, green extraction techniques, namely ultrasound-assisted, microwave-assisted and high pressure/temperature extractions, were compared with classic solid–liquid extraction. The extracts were characterized in terms of total polyphenols yield (TP) and the ARP. This study demonstrated that HPTE is the most efficient method to recover high-ARP phenolic-rich extracts from A. platensis biomass using green solvent (ethanol); therefore, may be used as a potential source of natural antioxidants to formulate functional foods or prepare dietary supplements, being a safe alternative to synthetic compounds.