The present study examines the behavior of a fluidic oscillator when operated within the compressible regime. Fundamentally, the internal dynamics remain unchanged from the incompressible regime. In the investigated oscillator, the internal velocities are always subsonic and converge to a maximum Mach number of 1 at the smallest outlet cross-section. Higher supply rate only cause an increase of the fluid’s density. Consequently, no shocks are present inside the oscillator. Furthermore, the oscillation frequency is a linear function of the local Mach number in the outlet nozzle. The oscillation frequency has an upper limit because the internal velocities are bound within the subsonic regime. A resonance frequency originating from a standing wave in the feedback channel exhibits a linear dependence on the outlet nozzle’s Mach number for the compressible regime. This suggests an interaction between the oscillation and the standing wave for higher supply rates which is not observed in the incompressible regime. For sufficiently high supply rates, a supersonic, overexpanded jet is present in the external flow field accompanied by characteristic phenomena such as oblique shocks and mach disks. The jet’s initial expansion causes the jet’s maximum deflection angle to be limited by the opening angle of the nozzle’s diverging part.