The applications of surfactant-free microemulsions (SFMEs) as solvents are reviewed, with a strong emphasis on recent research advancements. The discussion covers diverse research fields, including solubilization, extraction processes, use as reaction media, and fuel formulation. Particular attention is paid to mechanistic explanations proposed in the literature with respect to how SFMEs improve specific applications. Key parameters such as the structuring, solubility, and specific interactions are critically evaluated. Additionally, the review highlights the advantages and limitations of SFMEs compared to conventional solvents.