Animal feeding practices have changed considerably in the last decades to meet the escalating requirements of the ongoing population growth. As large-scale intensive animal breeding has become the popular animal husbandry, animal feeds have been modified to include high energy and protein contents, and to be stored for a longer period. These practices have led to many adverse effects, such as oxidative damage and mold contamination. The altered safety and nutritional quality of the feed urged animal feed compounders to use preservatives to combat the development of oxidative rancidity and microbial infestation. Conversely, the awareness of animal breeders and pet owners about the potential hazards of synthetic preservatives has evolved alongside the large-scale use of synthetic preservatives. This chapter endeavors to furnish a comprehensive review of the preservatives used in animal feed, pet food, and aquaculture, as well as the strengths and limits of natural and synthetic preservatives.