Bovine Thymic Stromal Lymphopoietin (TSLP) is a cytokine belonging to the IL-2 cytokine family, which also includes IL-2, IL-4, IL-7, IL-9, IL-15, and IL-21, molecules that regulate lymphocyte development and immune responses. In cattle (Bos taurus), TSLP is produced primarily by epithelial cells, stromal cells, and keratinocytes in barrier tissues such as the skin, respiratory tract, and gastrointestinal tract, particularly in response to infection, allergens, or inflammatory stimuli. TSLP signals through a heterodimeric receptor complex composed of the TSLP receptor (TSLPR/CRLF2) and the IL-7 receptor alpha chain (IL-7Rα), activating intracellular signaling pathways including JAK/STAT, particularly STAT5, which regulate immune cell differentiation and cytokine production. In bovine immune physiology, TSLP plays an important role in initiating and regulating type 2 immune responses, influencing dendritic cell activation and T helper cell polarization, particularly toward Th2-type responses. Through these actions, TSLP contributes to immune defense at epithelial barrier surfaces and may participate in responses to parasitic infections, allergens, and inflammatory conditions affecting cattle. Because epithelial immune signaling is critical for protecting livestock from environmental pathogens, bovine TSLP is studied in veterinary immunology, mucosal immunity, and host–pathogen interaction research, helping to improve understanding of immune regulation at barrier tissues in cattle.