This study conducted a 70-day feeding trial to evaluate the effects of dietary Lactobacillus plantarum supplementation (0, 0.1, 1.0, and 10.0 g/kg) in red claw crayfish (Cherax quadricarinatus). Growth performance, hepatopancreatic antioxidant-related parameters, and the expression of genes related to the Toll/Imd and JAK-STAT pathways were determined. Results showed that dietary L. plantarum supplementation significantly improved weight gain rate, specific growth rate, daily growth index, and f