School closings have been a key policy measure worldwide for reducing the spread of corona-virus disease (COVID-19). In Germany, federal states closed schools in mid-March and started to reopen them in late April. This policy potentially increased parental obligations for supervision and support during homeschooling and, thus, might reinforce social inequality in educational opportunities. Therefore, this research note investigates social inequality in students’ homeschooling efforts. Moreover, it asks whether social disparities in home learning environments, social support, teacher support, and cost–benefit-related considerations account for the social differences in homeschooling efforts during the school closing period in Germany. To that end, we use data from an ongoing research project on high school students in their final years that were collected during the school closing period. Our results show pronounced differences in home schooling efforts by social background. Thus far, the mechanisms under study can explain only a moderate part of the social origin effect. In summary, the results show that school closings have the potential to exacerbate social inequality in educational opportunities. Therefore, future research should scrutinise the extent to which school closings reinforce inequality in educational opportunities.