Ionic liquids (ILs) have unique properties such as structural tunability, good solubility, chemical/thermal stability, favorable biocompatibility, and simplicity of preparation, making them suitable for pharmaceutical and biomedical applications. They can improve drug solubility, stability, and delivery efficiency, addressing issues like poor drug solubility and low bioavailability. This review discusses recent advancements in ILs for drug synthesis, analysis, solubilization, and crystal engineering, as well as their biomedical applications in drug delivery, protein stabilization, antimicrobial agents, and bioactive ILs. ILs are categorized into generations based on their chemical structure and properties. The first generation has low biodegradability and high toxicity, while the third generation has low toxicity and good biodegradability. ILs are used as solvents, catalysts, and reaction media in drug synthesis, improving reaction rates and yields. They are also used in drug extraction and analysis, offering advantages over traditional solvents. In drug solubilization, ILs can enhance drug penetration through physiological barriers. In drug crystal engineering, ILs can control crystal form and improve crystal habit. In biomedical applications, ILs are used as drug delivery vehicles, improving drug bioavailability and reducing side effects. They are also used in microemulsions and micelles for drug delivery, enhancing transdermal penetration and stability. Overall, ILs show great potential in pharmaceutical and biomedical applications due to their tunable properties and environmental benefits.Ionic liquids (ILs) have unique properties such as structural tunability, good solubility, chemical/thermal stability, favorable biocompatibility, and simplicity of preparation, making them suitable for pharmaceutical and biomedical applications. They can improve drug solubility, stability, and delivery efficiency, addressing issues like poor drug solubility and low bioavailability. This review discusses recent advancements in ILs for drug synthesis, analysis, solubilization, and crystal engineering, as well as their biomedical applications in drug delivery, protein stabilization, antimicrobial agents, and bioactive ILs. ILs are categorized into generations based on their chemical structure and properties. The first generation has low biodegradability and high toxicity, while the third generation has low toxicity and good biodegradability. ILs are used as solvents, catalysts, and reaction media in drug synthesis, improving reaction rates and yields. They are also used in drug extraction and analysis, offering advantages over traditional solvents. In drug solubilization, ILs can enhance drug penetration through physiological barriers. In drug crystal engineering, ILs can control crystal form and improve crystal habit. In biomedical applications, ILs are used as drug delivery vehicles, improving drug bioavailability and reducing side effects. They are also used in microemulsions and micelles for drug delivery, enhancing transdermal penetration and stability. Overall, ILs show great potential in pharmaceutical and biomedical applications due to their tunable properties and environmental benefits.