Self-regulation was found to be positively associated with school performance. Interrelations between self-regulation, working memory (WM), and achievement goals, in particular mastery goals, have been established, as well as associations with academic outcomes. It stands to reason that self-regulation, WM, achievement goals, and academic success are related on a daily level. However, previous research rarely considered this level of analysis. Here, we therefore addressed the relations of daily self-regulation, WM, and achievement goals, and their relevance for daily and general academic success. Data were obtained through ambulatory assessments in 90 students before (Study 1; M[subscript age] = 9.83, SD[subscript age] = 0.50) and 108 students after their transition to secondary school (Study 2; M[subscript age] = 10.12, SD[subscript age] = 0.45) across 20 school days. Students reported about daily achievement goals prior to school, self-regulation at school, and perceived academic success after school, as well as report card grades. Daily WM was assessed at school. Study 1 showed positive associations between daily mastery goals and self-regulation, but not with WM. Together, daily performance-approach goals and self-regulation, but not other goals or WM uniquely contributed to daily perceived academic success. Study 2 showed positive associations between daily mastery goals and self-regulation, but not with WM. Average daily mastery goals predicted daily WM. Together, daily mastery goals and self-regulation, but not WM, uniquely contributed to daily perceived academic success. In both studies, average levels of WM, but not achievement goals or self-regulation predicted report card grades. Results thus corroborate theoretical considerations on the importance of distinguishing self-regulation processes at between- and within-person levels.