Smartphones cause self-control challenges in people's everyday lives. Supporting this notion, our studies corroborate that trait self-control is negatively associated (1) with students' distraction (via smartphones) during their learning endeavors (Study 1, N = 446) and (2) with several aspects of problematic smartphone-use (Study 2, N = 421). Study 3 (N = 106) investigated whether distinct aspects of smartphone-use also account for the link between students' trait self-control and academic performance. Specifically, we examined (1) smartphone procrastination (i.e., irrational task delays via smartphone), (2) beneficial smartphone habits (placing in a bag [placement habit] or turning the sound off [setting habit]), and (3) the objective amount of smartphone-use (minutes spent on the smartphone [screentime] and times picked up [pickups]). In line with our predictions, students higher in trait self-control showed better academic performance (β = 0.22). Smartphone procrastination (β = −0.23) and placement habits (β = 0.21) were significantly associated with academic performance and both also mediated the self-control-performance-link. Our findings suggest that it is not the objective amount of smartphone-use but the effective handling of smartphones that helps students with higher trait self-control to fare better academically. Implications for future research are discussed from a self-regulatory perspective on smartphone-use.