This study investigated changes in learning enjoyment and learning effort, two central yet under-researched aspects of school-related emotion and motivation, before and during the COVID-19 pandemic. It also verified whether selected aspects of the home environment predicted changes in the two aspects. To this end, we used data gathered from 4240 German lower secondary school students surveyed before (Grade 7, 2018/19) and during the COVID-19 pandemic (Grade 8, 2019/20 and Grade 9, 2020/21). The analyses, which involved latent change score models with covariates, revealed a decrease in student learning enjoyment and learning effort between Grades 7 and 9. Moreover, the student-perceived consequences of the pandemic predicted a decrease in both of these constructs, whereas parental ability to provide learning support during distance learning predicted a decrease in learning enjoyment. The strength of this relationship depended on prior student academic achievement. The results highlight the role of environmental factors for the development of learning enjoyment and learning effort.