Self-regulation refers to a complex set of processes that control attentional, emotional, and behavioral impulses. Understandably, studies have shown that these processes have a significant impact on an individual's success in school environments. Further, research has highlighted that self-regulation processes are developmental and dynamic, gradually shaped over time by experiences and environments. Thus, unexpected disruptions to environments and expected experiences can negatively impact the development of self-regulation and produce negative secondary consequences, such as learning loss. The COVID-19 pandemic brought about unexpected disruptions to the lives of most people. Emerging research demonstrates the toll the pandemic took on individuals' physical and mental health, work, connections to others, and finances. For a generation of students, there was an additional impact of school closures, shifts to online learning, and social distancing from peer groups. In the present study, I examined how COVID-19 related stress and impacts interacted with the self-regulation of students in grades four through ten. Utilizing data from an ongoing longitudinal study, I fitted a series of multilevel models to evaluate whether COVID-19 stressors and impacts were predictive of worse student self-regulation and whether this had a negative effect on students' mathematics competence as measured by their performance on grade level assessments. Results indicated that student self-regulation was a reliable and robust predictor of performance on grade-level mathematics competence measures. COVID-19 related impacts were associated with worse self-regulation, though COVID-19 stress did not have an effect on self-regulation. We found no evidence of significant interaction effects between COVID-19 related stress and impacts on the relationship between self-regulation and mathematics outcomes. This dissertation study contributes to a growing body of research aimed at understanding the far-reaching consequences of the COVID-19 pandemic, particularly for a generation of students whose learning, social, and home environments were disrupted. Future research should continue to examine self-regulation processes and learning consequences of COVID-19 as we are likely to observe ongoing effects for years to come. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]