Nitrous oxide (N2O) is a potent greenhouse gas, and its efficient capture is crucial for climate mitigation. Imidazoliumbased ionic liquids (ILs) offer tunable physicochemical properties, making them promising candidates for N2O absorption. 

However, systematic screening and molecular-level understanding of IL-N2O interactions remain limited. In this work, experimental N2O solubility in imidazolium-based ILs are collected to evaluate the COSMO-RS predictive performance, which is further improved via linear correction. Using the calibrated model, 760 ILs are virtually screened. The effects of IL structural variations on N2O solubility are investigated and interpreted via σ-profile analyses. Top three ILs with high N2O solubility and favorable physical properties are identified, demonstrating the potential for rational IL screening. The absorption mechanism of the top-performing ILs is analyzed using COSMO-RS-calculated interaction energies and independent gradient model (IGM) visualizations. The combined computational and mechanistic approach provides a reliable framework for identifying promising ILs for efficient N2O capture.