The extraction and isolation of natural antioxidants with potential in reducing the incidences of oxidative stress in the body and their potential inclusion into functional foods is a major topic of research at present. In this study, the aim was to investigate food-friendly Accelerated Solvent Extraction^® (ASE^®) samples and a Viscozyme^® hydrolysate of the brown macroalga "Fucus spiralis" Linnaeus for total phenolic content and antioxidant activities. Furthermore, the effect of ultra-filtration steps on the total phenolic content and antioxidant activities of the "Fucus spiralis" hydrolysate were also evaluated. "Fucus spiralis" ethanolic-aqueous and methanolic-aqueous ASE^® extracts displayed high phenolic contents of 37.03 ± 3.01 and 39.04±5.72 μg phloroglucinol equivalents mg/sample, respectively. Both the "Fucus spiralis" Viscozyme^® hydrolysate and ASE^® extracts displayed "in vitro" antioxidant activities. Our findings suggest that food-friendly extracts of "Fucus spiralis" show potential as alternative sources of antioxidants.