Bovine Oncostatin M (OSM) is a multifunctional cytokine belonging to the IL-6 family of cytokines, which also includes IL-6, IL-11, leukemia inhibitory factor (LIF), cardiotrophin-1 (CT-1), ciliary neurotrophic factor (CNTF), cardiotrophin-like cytokine factor 1 (CLCF1), and IL-27. In cattle (Bos taurus), OSM signals through receptor complexes containing the shared gp130 subunit, typically pairing with OSM receptor (OSMR) or LIF receptor (LIFR), leading to activation of intracellular signaling pathways such as JAK/STAT3, MAPK, and PI3K. Bovine OSM is produced primarily by activated T cells, macrophages, and neutrophils and plays roles in inflammation, hematopoiesis, and tissue remodeling. In bovine health, OSM-mediated signaling contributes to regulation of immune responses during mastitis, bovine respiratory disease complex (BRDC), and other inflammatory conditions, where it can influence leukocyte activation, cytokine production, and tissue repair. OSM may also participate in fibrotic responses and regulation of epithelial and stromal cell function during chronic inflammation. As a member of the IL-6 cytokine family involved in immune regulation and tissue remodeling, bovine OSM is important for studies of host–pathogen interactions, inflammatory disease mechanisms, and cytokine signaling pathways relevant to cattle health and productivity.