Purpose: Physical education (PE) teachers’ assessments are often based on continuous observations of pupils. As certain psychological factors may mediate pupils’ learning behaviors relevant to the PE context, they may also influence academic achievement in PE. Thus, this study’s aim was to explore the association between pupil-related psychological factors and academic achievement in PE. Methods: Eighty-nine boys and 111 girls (12–16 years old) in lower secondary school participated in this study, responding to a questionnaire containing previously validated scales measuring pupils’ grit, mindset, self-perceptions, and situational motivation. The pupils’ final grade in PE was collected at the end of the school year. Results: A multiple regression model significantly explained 33% of the variance in grade. The self-perception domains—scholastic competence, athletic competence, and physical appearance—acted as unique predictors, explaining a small portion of the variance in academic achievement. Discussion/conclusion: These results support the importance of positive self-perceptions in relation to academic achievement in PE.