BACKGROUND Under the intensive modern poultry farming system, the lung of duck is one of the main target organs for various bacterial and viral infections. Curcumin is a kind of natural polyphenol compound for which various beneficial biological functions exist, including being an anti‐inflammatory, antioxidant, and antiviral. The aim of this work was to investigate the mechanism of curcumin‐alleviated lipopolysaccharide (LPS)‐induced lung damage by the nuclear erythroid 2‐related factor 2 (Nrf2)‐antioxidant reaction element (ARE) and nuclear factor kappa B (NF‐κB) signaling pathway in ducks. RESULTS In total, 450 one‐day‐old male specific pathogen‐free ducks were randomly assigned into three dietary treatments: CON, basal diet; LPS, basal diet + LPS treatment; LPS + CUR, basal diet + LPS + 500 mg kg−1 of curcumin. At the end of the experiment (21 days), ducks in LPS treatment were challenged with 5 mg LPS per kilogram of body weight and the other two treatments were injected with the same dose of phosphate‐buffered saline solution. The results showed that LPS caused acute inflammation, oxidation stress, and lung injury. Dietary addition of curcumin significantly relieved the oxidation stress and inflammation parameters. Moreover, the results showed that remission may be through the signaling pathways of both Nrf2‐ARE and NF‐κB. CONCLUSION In conclusion, dietary supplementation of 500 mg kg−1 of curcumin exhibited a lung‐protective effect in ducks. This experiment broadens the mode of metabolism actions of curcumin in the target organs and provides an insight for the application of curcumin in waterfowl feed. © 2022 Society of Chemical Industry.