Exposure to mycotoxins can pose a variety of adverse health effects to mammals. Despite dozens of mycotoxin decontamination strategies applied from pre- to postharvest stages, it is always challenging to guarantee a safe level of these natural toxic compounds in food and feedstuffs. In the context of the increased occurrence of drug-resistance strains of mycotoxin-producing fungi driven by the overuse of fungicides, the search for new natural-product-based solutions is a top priority. This review aims to shed a light on the promising potential of stilbenoids extracted from renewable agricultural wastes (e.g., grape canes and forestry byproducts) as antimycotoxin agents. Deeper insights into the mode of actions underlying the bioactivity of stilbenoid molecules against fungal pathogens, together with their roles in plant defense responses, are provided. Safety aspects of these natural compounds on humans and ecology are discussed. Perspectives on the development of stilbenoid-based formulations using encapsulation technology, which allows the bypassing of the limitations related to stilbenoids, particularly low aqueous solubility, are addressed. Optimistically, the knowledge gathered in the present review supports the use of currently underrated agricultural byproducts to produce stilbenoid-abundant extracts with a high efficiency in the mitigation of mycotoxins in food and feedstuffs.