Rabbit BAFF (B cell–Activating Factor), also known as BLyS or TNFSF13B, is a member of the tumor necrosis factor (TNF) superfamily and plays a critical role in B cell development, survival, and regulation of humoral immunity in rabbits (Oryctolagus cuniculus). BAFF is produced primarily by monocytes, macrophages, dendritic cells, neutrophils, and certain stromal and epithelial cells, and it signals through the receptors BAFF-R (TNFRSF13C), TACI (TNFRSF13B), and BCMA (TNFRSF17) to promote transitional and mature B cell survival, immunoglobulin class switching, and maintenance of long-lived plasma cells. In rabbits—widely used for polyclonal and monoclonal antibody production—BAFF supports robust antibody responses and contributes to mucosal immunity, including IgA production. Dysregulated BAFF expression may be associated with chronic inflammation, autoimmune-like conditions, or B cell–related proliferative disorders in experimental models. In biomedical and translational research, rabbit BAFF is of particular interest in studies of vaccine immunogenicity, antibody production, mucosal immunity, and comparative B cell biology. Characterizing BAFF signaling in rabbits provides valuable insight into regulation of humoral immune responses and strategies to modulate B cell–mediated immunity in research settings.