In this review, antimicrobials from a range of plant, animal, and microbial sources are reviewed 10 along with their potential applications in food systems. Chemical and biochemical antimicrobial 11 compounds derived from these natural sources and their activity against a range of pathogenic and 12 spoilage microorganisms pertinent to food, together with their effects on food organoleptic proper- 13 ties, are outlined. Factors influencing the antimicrobial activity of such agents are discussed 14 including extraction methods, molecular weight, and agent origin. These issues are considered in 15 conjunction with the latest developments in the quantification of the minimum inhibitory (and 16 noninhibitory) concentration of antimicrobials and/or their components. Natural antimicrobials can 17 be used alone or in combination with other novel preservation technologies to facilitate the 18 replacement of traditional approaches. Research priorities and future trends focusing on the impact 19 of product formulation, intrinsic product parameters, and extrinsic storage parameters on the design 20 of efficient food preservation systems are also presented.