Chicken CCL20 (C-C motif chemokine ligand 20, also known as MIP-3α, macrophage inflammatory protein-3 alpha, or LARC – liver and activation-regulated chemokine) is a pro-inflammatory chemokine that plays an important role in mucosal immunity and leukocyte recruitment in chickens (Gallus gallus). CCL20 primarily signals through the CCR6 receptor, promoting chemotaxis of immune cells including immature dendritic cells, memory T cells, and certain B cell populations to sites of infection or epithelial inflammation. In poultry, CCL20 is strongly expressed in epithelial tissues such as the intestinal tract, respiratory mucosa, and skin, where it contributes to the early immune response against pathogens. It is particularly relevant in infections caused by Eimeria spp. (coccidiosis), avian influenza virus, Newcastle disease virus, and bacterial pathogens such as Salmonella and Campylobacter, where epithelial cells produce CCL20 to recruit immune cells and coordinate local inflammatory responses. While CCL20-mediated leukocyte trafficking supports pathogen clearance and mucosal defense, excessive expression may contribute to epithelial inflammation and tissue damage. As a biomarker of mucosal immune activation, chicken CCL20 is widely studied in investigations of host–pathogen interactions, intestinal immunity, and vaccine responses in poultry. Characterization of chicken CCL20 therefore supports research aimed at improving disease resistance, mucosal vaccine strategies, and overall flock health in commercial poultry systems.