Changes in personality traits in late adolescence and young adulthood are believed to co-occur with changes in identity, but little research is available that supports this hypothesis. The present study addressed this relatively understudied area of research by examining longitudinal associations of Big Five personality traits (i.e., Neuroticism, Extraversion, Openness, Agreeableness, and Conscientiousness) with dimensions of identity formation (i.e., identification with commitment and exploration in depth) in the domain of education. For this purpose, we used four annual waves of longitudinal data on 485 Belgian late adolescents (87.4% female; mean age at T1 = 18.6 years) covering a 3-year period. Multivariate growth models revealed that changes in Big Five personality traits were related to changes in identification with commitment and exploration in depth. Cross-lagged panel models uncovered that, except for Openness, all Big Five traits predicted educational identity dimensions. Educational identity dimensions only predicted Neuroticism. In addition, adolescents with higher levels on the personality trait of Conscientiousness faced fewer study delays. In sum, the present study adds to the growing literature that explores the antecedents, correlates, and consequences of personality trait development by uncovering the interplay of personality traits, educational identity dimensions, and academic progress in late adolescents.