Circuit and methods for automatic clock skew compensation in circuits having two power domains. When one of the power domains is operated with a lowered supply voltage, lowering the supply voltage tends to slow the clock pulse and produces clock skew. Circuitry is provided for selectively delaying the clock pulse in one of the power domains to reduce the clock skew by comparing the clock pulses, and then automatically delaying the clock pulse in one of the domains by a delay determined to minimize the skew. A method is provided where the clock skew between two clock pulses is determined and the delay needed in one of the clock pulses to reduce the skew is determined by sampling the clock skew using a plurality of delays at multiples of a minimum delay, and then automatically delaying the one clock pulse by selecting an appropriate delay. The method may be iterated.