<p>The growing restrictions on in-feed antibiotics and the global rise of antimicrobial resistance have intensified the demand for safe and sustainable alternatives to support animal health and productivity. Paraprobiotics, defined as non-viable or inactivated bacterial cells, have recently emerged as a promising class of functional bioactives capable of conferring health benefits without the risks associated with live probiotics. Unlike conventional probiotics, paraprobiotics mediate their effects through intact cell structures and microbial metabolites that engage host pattern-recognition receptors, thereby modulating both innate and adaptive immune responses. This review critically examines the antimicrobial efficacy of paraprobiotics in poultry, emphasizing their mechanistic role in maintaining gut barrier integrity, regulating microbial ecology, and mitigating inflammation-induced oxidative stress. Evidence indicates that paraprobiotics suppress pathogenic colonization enhance epithelial function, stimulating antimicrobial peptide production, and improve nutrient utilization and growth performance. Moreover, their stability during feed processing, prolonged shelf-life, and minimal risk of horizontal gene transfer further enhance their suitability for large-scale, intensive production systems. Additionally, emerging inactivation technologies, optimized dosing strategies, and synergistic applications with prebiotics and phytobiotics offer avenues to maximize their functional potential. Collectively, paraprobiotics exemplify a paradigm shift in antimicrobial nutrition providing “dead cells with living functions” that combine safety, efficacy, and sustainability. Their integration into antibiotic-free poultry system hold significant promise for enhancing disease resilience, productive performance and overall sustainability of modern poultry production.</p>