Research revealing that seaweed fermentation can be used to create novel food and nutraceutical products that demonstrate high bioactivity and sensory quality was presented. The studies included demonstrate the use of this process in algal tissues and extracts as an enhancer of antioxidant, antimicrobial, anti-inflammatory and antidiabetic activities, among others. Many of the difficulties related to fermenting seaweed have been addressed by research within the field of biofuels, providing insight on the conditions and pre-treatments necessary to improve seaweed fermentability. Food applications for seaweed fermentation products are still underdeveloped, but the nutritional, sensory and bioactive profiles collected so far highly encourage further developments.