Key PointsQuestionIs healthy sleep, both before and during the COVID-19 pandemic, prior to SARS-CoV-2 infection, protective against post–COVID-19 condition (PCC)?FindingsIn this cohort study of 1979 women who reported testing positive for SARS-CoV-2, adherence to healthy sleep before infection was inversely associated with the risk of PCC. Compared with women who had a prepandemic sleep score of 0 or 1 (least healthy), those who scored 5 (most healthy) had a 30% lower risk of PCC.MeaningThese findings suggest that preinfection healthy sleep may be associated with a substantially decreased risk of PCC, indicating a need for further research on sleep health to prevent or improve symptoms of PCC.