We investigate the stability of self-control at the population level. Analyzing repeated Brief Self-Control Scale scores, we demonstrate that self-control exhibits a high degree of mean-level, rank-order, and individual-level stability over the medium term. Changes in self-control are not associated with major life events, nor are they economically important. The stability of self-control is particularly striking given our study period (2017-2020) spans the onset of the COVID-19 pandemic.