Background. Lockdowns and physical distancing have dramatically limited the circulation of SARS-CoV-2 and other common communicable infections. However, little is known about their impact on head lice and scabies. Aim. To assess the impact of the 2020 French National lockdowns (17 March-11 May 2020, and 30 October-15 December 2020) and physical distancing recommendations (from February 2020) on the dynamics of head lice and scabies infestations. Methods. The weekly sales of topical head lice treatments, topical scabies treatments and oral ivermectin were extracted from the database of the healthcare science company IQVIA (60% of all French retail pharmacies) and analysed over a 5-year period (March 2016-December 2020). A periodic regression model was fitted to drug sales before the COVID-19 period (2016-2019) and extrapolated to compare the observed sales in 2020 to the expected sales. Results. A decrease of the sales of tracer topical treatments for head lice and scabies was observed from March 2020, synchronously with the first French national lockdown. For the period March-December 2020, the mean reduction in observed vs. expected sales for head lice and scabies topical treatments was 44% and 14%, respectively. By contrast, although there was an observed decrease in oral ivermectin sales after March 2020, it was much lower (4%), probably because of studies reporting the potential positive effects of this drug on COVID-19 infection. Conclusion. COVID-19 lockdown and physical distancing reduce circulation of head lice and scabies in France. Further studies are needed to assess the long-term impact of these social behaviour changes.