Phenolic antioxidants have increasing attention in the food industry as functional food additives or as alternative preservatives. Plant residues, including various food processing wastes, can contain such chemicals in high amount, but most of them are in glycosidic form having reduced bioavailability. Numerous studies have reported that the solid-state fermentation with cellulolytic fungi and the carbohydrase-assisted extraction are exploitable techniques for mobilization of phenolics from glycosides. The extracted phenolic compounds can enhance the stability and shelf life of food products, increase their antioxidative capacity, and inhibit the growth of a range of microorganisms. This chapter aims to highlight the relevance of fermentation and enzyme-catalyzed approaches in bioactive phenolics production from plant materials. In line with this, antioxidative plant residues as potential phenolics sources, as well as fermenting fungi and enzymes suitable for the high yield production have been presented in detail. Factors determining the effectiveness of treatments, some combination studies with conventional extraction procedures, and possibilities for the ecofriendly production of carbohydrase cocktails have been discussed.