Chicken CCL19 (C-C motif chemokine ligand 19), also known as macrophage inflammatory protein-3β (MIP-3β) or EBI1 ligand chemokine (ELC)-like in avian species, is a member of the CC chemokine family that plays a key role in lymphocyte trafficking and organization of secondary lymphoid tissues in chickens (Gallus gallus). CCL19 is expressed primarily by stromal cells, dendritic cells, and macrophages within lymphoid organs such as the spleen, cecal tonsils, thymus, and the bursa of Fabricius. It functions through a CCR7-like receptor to direct migration of naïve T cells, central memory T cells, and mature dendritic cells to lymphoid tissues, facilitating antigen presentation and initiation of adaptive immune responses. In healthy chickens, CCL19 supports immune surveillance and maintenance of lymphoid architecture; expression may increase during infection, vaccination, or inflammatory stimulation. In poultry immunology research, chicken CCL19 is particularly relevant in studies of vaccine-induced immunity and host responses to pathogens such as Marek’s disease virus (MDV), infectious bursal disease virus (IBDV), avian influenza virus, and enteric pathogens. Characterization of CCL19 in chickens provides valuable insight into CCR7-mediated immune cell trafficking, lymphoid tissue organization, and adaptive immune regulation in avian health and production systems.