Chicken CCL5 (C–C motif chemokine ligand 5, also known as RANTES – Regulated upon Activation, Normal T cell Expressed and Secreted) is a proinflammatory chemokine involved in immune cell recruitment and inflammatory responses in chickens (Gallus gallus). CCL5 is a member of the CC chemokine family, which includes related chemokines such as CCL3, CCL4, and CCL2, all of which regulate leukocyte trafficking during immune activation. In chickens, CCL5 is produced primarily by activated T lymphocytes, macrophages, dendritic cells, and epithelial cells in response to infection, inflammatory stimuli, or tissue damage. CCL5 functions mainly by binding to chemokine receptors such as CCR1 and CCR5, triggering intracellular signaling pathways that promote chemotaxis and activation of T cells, monocytes/macrophages, and other immune cells at sites of infection or inflammation. In avian immunity, CCL5 plays a role in responses to viral, bacterial, and parasitic pathogens, including important poultry diseases such as avian influenza virus, Newcastle disease virus, and Eimeria infections, where recruitment of immune cells is critical for pathogen control. Because chickens are widely used in avian immunology and host–pathogen interaction studies, chicken CCL5 is studied in research on chemokine signaling, inflammatory responses, and vaccine-induced immunity, contributing to improved understanding of immune regulation and disease resistance in poultry.