Cranberry pomace is a waste product from the cranberry juice processing industry. It contains a range of phenol antioxidants which may be of use for the control of food-borne pathogens. Previous research has shown that solid-state fermentation of cranberry pomace by Rhizopus oligosporus improves its phenol and antioxidant profiles, and, in this study, the release of phenol aglycones during this fermentation was assessed in relation to changes in antioxidant functionality, diphenyl mobilization and antimicrobial activity against Listeria monocytogenes, Vibrio parahaemolyticus and Escherichia coli O157:H7. After a 20-day fermentation, pomaces were tested for changes in phenol levels and profiles, antioxidant potential and antimicrobial activities. Pomace fermentation increased levels of soluble phenols generally and ellagic acid in particular, whilst antioxidative activity was also increased. Antimicrobial activity towards E. coli was correlated with ellagic acid levels and antioxidative activity as measured by DPPH, whilst antimicrobial activity towards the other 2 pathogens was correlated with soluble phenols and antioxidative activity as measured by beta-carotene oxidation. It is suggested that these differences may reflect membrane hyperacidification-based and membrane transport disruption-based modes of inhibition, respectively. Possible use of this fermented cranberry waste as an antimicrobial ingredient in foods and feeds is discussed.