The growing interest in biomimicry in flow control has created opportunities for more innovative designs. Humpback whale tubercles are particularly distinctive. This biomimetic modification in airfoils has been extensively studied in the subsonic regime and is well known for its ability to delay stall. However, it has not received the same level of engineering attention as transonic flow. The purpose of this study is to determine whether the stall-delaying effect persists in the transonic regime and to evaluate its performance as the amplitude of the tubercles increases. Six configurations were tested, with amplitude-to-chord length (c) ratios ranging from 0.025 to 0.25. A simulation study was conducted using ANSYS Fluent and the SST k-ω turbulence model to determine the aerodynamic performance. The configuration with the smallest tubercle amplitude (0.025c) outperformed the others. It reduced drag significantly (30% at Mach 0.8) and improved the lift-to-drag ratio (CL/CD) from l° to 3° AoA (+37.8% at 1° AoA) when compared to the baseline. Tubercles were found to influence shock structures, with valleys and peaks tending to weaken or delay them. Increasing tubercle amplitude beyond this optimum (beyond 0.1c) generally resulted in performance degradation, including lower lift, increased drag (0.25c configuration exhibited up to 40% more drag than the baseline at Mach 0.9), and adverse flow phenomena such as intensified shock–boundary layer interactions, flow separation, and more chaotic vortex formation. This study suggests that leading-edge tubercles could be used in high-speed flight.