The COVID-19 lockdown saw an increased reliance on digital technology for children, which might have called for changes in parental mediation practices. The present study aimed at analyzing the extent to which such changes took place, their predictors, and their differences across countries. Data were collected from 2,412 parents and 2,412 children in Austria, Ireland, Norway, Portugal, and Romania. Results showed that on average 48.3% of parents used mediation practices with the same frequency as before the lockdown, while 38% applied more mediation. Both active and restrictive mediation were predicted by children’s time online, parents’ worry about risks, parents’ technology fatigue, and parent-child involvement. Furthermore, restrictive mediation was predicted by risks encountered online by children, while active mediation was predicted also by children’s excessive Internet use. Differences in parental mediation changes were observed across countries.