Canonical Wnt signaling plays a major role in regulating microbial pathogenesis. However, to date, its involvement inA. hydrophilainfection is not well known. Using zebrafish (Danio rerio) kidney macrophages (ZKM), we report thatA. hydrophilainfection upregulateswnt2,wnt3a,fzd5,lrp6,and β-catenin (ctnnb1) expression, coinciding with the decreased expression ofgsk3bandaxin. Additionally, increased nuclear β-catenin protein accumulation was observed in infected ZKM, thereby suggesting the activation of canonical Wnt signaling inA. hydrophilainfection. Our studies with the β-catenin specific inhibitor JW67 demonstrated β-catenin to be pro-apoptotic, which initiates the apoptosis ofA. hydrophila-infected ZKM. β-catenin induces NADPH oxidase (NOX)-mediated ROS production, which orchestrates sustained mitochondrial ROS (mtROS) generation in the infected ZKM. Elevated mtROS favors the dissipation of the mitochondrial membrane potential (ΔΨm) and downstream Drp1-mediated mitochondrial fission, leading to cytochromecrelease. We also report that β-catenin-induced mitochondrial fission is an upstream regulator of the caspase-1/IL-1β signalosome, which triggers the caspase-3 mediated apoptosis of the ZKM as well asA. hydrophilaclearance. This is the first study suggesting a host-centric role of canonical Wnt signaling pathway inA. hydrophilapathogenesis wherein β-catenin plays a primal role in activating the mitochondrial fission machinery, which actively promotes ZKM apoptosis and helps in containing the bacteria.