SummaryA relaxation oscillator using a memristor is hereby presented. The memristor is used to substitute the function of a capacitor in an equivalent RC oscillator. The voltage across the memristor changes according to the quantity and polarity of the current passing through, thus substituting the changing voltage across a capacitor in the equivalent RC oscillator. The memristor has the advantage of occupying much less area than the equivalent capacitor, which may be important when trying to build on‐chip oscillators for portable or medical applications. Copyright © 2014 John Wiley & Sons, Ltd.