Supersonic combustors are gaining increasing attention due to their advantages over subsonic combustors, ramjets, and rocket engines operating within the atmosphere. While various fuels—including gaseous and liquid—have been explored for such applications, each category presents distinct limitations. Supercritical fuels offer a promising alternative, combining the benefits of both gaseous and liquid fuels while mitigating many of their drawbacks. However, the behaviour of supercritical fuels in supersonic flows remains insufficiently characterized. This study investigates the injection of supercritical Jet A fuel into a Mach 2 cold-flow supersonic wind tunnel. Flow visualization techniques, including high-speed schlieren and focusing schlieren, are employed to examine jet penetration, shock structures, and the influence of injection parameters. The results provide new insights into jet–crossflow interactions under near-critical thermodynamic conditions and contribute to the fundamental understanding required for the design of high-performance supersonic combustion systems.