We developed a composite consisting of mesoporous ZrO2 thin films supporting catalytically active gold nanoparticles (Au NPs) for the oxidative removal of carbon monoxide (CO). At first, highly ordered mesoporous ZrO2 (m-ZrO2) thin films are prepared by sol-gel-based spin-coating process followed by a controlled thermal treatment process in air. Then, Au NPs are successfully dispersed and deposited over the entire framework of mesoporous ZrO2 thin films to form Au/m-ZrO2 films. The specific surface area and crystallinity of the m-ZrO2 thin films as well as the periodicity of the mesoporous framework can be controlled by adjusting the calcination temperature and the synthetic parameters. The catalytic efficiency of the optimized Au/m-ZrO2 composite film toward CO conversion reaches 94% of circulation time, and is well-retained even after 1 h (���88%).