Ionic liquids (ILs) and supercritical CO2 (scCO(2)) are two promising types of reaction media for green chemical processes due to their unique properties. They can be integrated into chemical reactions as catalysts and solvents to develop green and environment-friendly processes. This review presents current research trends aiming to solve the major chemical engineering issues in light of a fundamental understanding of these media. Applications of these media in the petrochemical industry, biochemical engineering, and fine chemical production are reviewed, suggesting the challenges and directions of utilizing them for green processes prospectively. These recent explorations and successful examples of applications demonstrate that ILs and scCO(2) offer huge potential for novel and green chemical engineering processes.