Methods and systems for utilizing undersampling for crystal leakage cancellation are disclosed and may include undersampling a composite signal comprising a desired signal and leakage signals due to one or more clock signals. Measured DC signals generated by each of the undersampled signals may be reduced by adjusting the phase and/or amplitude of the clock signals. The undersampling may be performed at one or more of the one or more clock signals, or at integer sub-harmonics of the clock signals. The composite signal may include a signal received by a wireless system or a signal to be transmitted by the wireless system. The undersampled signals may be low-pass filtered. The desired signal may include in-phase and quadrature signals or a polar signal. The undersampling may be performed by one or more sample and hold circuits and the clock signals may be generated utilizing one or more crystal oscillators.