Techniques for on-chip detection of integrated circuit power supply noise are disclosed. By way of example, a technique for monitoring a power supply line in an integrated circuit includes the following steps/operations. A first signal and a second signal are preconditioned. The first signal is representative of a voltage of the power supply line being monitored. The second signal is representative of a voltage of a reference power supply line. Preconditioning includes shifting respective levels of the voltages such that the voltages are within an input voltage range of comparator circuitry. Then, the preconditioned first signal and the preconditioned second signal are compared in accordance with the comparator circuitry. Comparison includes detecting when a difference exists between the voltage level of the preconditioned first signal and the voltage level of the preconditioned second signal.