The effects of dietary palygorskite (Pal) supplementation on growth performance, oxidative status, and intestinal barrier function in ducks were investigated. In total, 720 one-day-old Cherry Valley ducks were categorized into 4 treatments comprising 6 replicates with 30 ducks each. Ducks were fed a basal diet supplemented with 0, 5, 10, or 20 g/kg Pal for 42 days. Twenty-four ducks (1 male/replicate) were slaughtered at 14 and 42 days and samples were collected for analysis. Pal supplementation quadratically increased weight gain and linearly and quadratically increased feed intake (P < 0.05) during the starter period. Pal enhanced serum glutathione peroxidase activity (GSH-Px) at 14 (linear and quadratic, P < 0.05) and 42 days (linear, P < 0.001), and lowered serum malondialdehyde (MDA) content at 14 and 42 days (quadratic, P < 0.05). It enhanced 42-day liver superoxide dismutase activity (linear, P = 0.003) and GSH-Px activity at 14 (quadratic, P = 0.044) and 42 days (linear and quadratic, P < 0.001), but decreased 14-day liver MDA content (quadratic, P = 0.003). Pal reduced 42-day serum diamine oxidase activity (linear and quadratic, P < 0.05) and serum endotoxin content at 14 (linear and quadratic, P < 0.05) and 42 days (quadratic, P = 0.017). It linearly and quadratically increased jejunal mucosal immunoglobulin (Ig) M at 42 days and IgG at 14 and 42 days, and 42-day ileal mucosal IgG and secretory IgA (P < 0.05). Ileal mucosal IgM content was quadratically increased at 14 and 42 days (P < 0.05) by Pal. Moreover, Pal enhanced the mRNA expression of 14-day occludin in the jejunal mucosa (quadratic, P = 0.033) and that of 42-day zonula occludens-1 in the ileal mucosa (linear, P = 0.027). Thus, dietary Pal supplementation exerts beneficial effects through improving growth performance, antioxidant capacity, and intestinal barrier function of ducks.