Background <p>Academic performance (AP) is a crucial indicator of success among nursing students, directly influencing their professional development and the quality of patient care they will deliver. While smartphone addiction (SA) and poor sleep quality (SQ) have each been linked to diminished AP, the mediating role of SQ in this relationship remains poorly understood, especially in North African contexts.</p> Objective <p>This study aimed to investigate the mediating role of SQ in the relationship between SA and AP among nursing students in Meknes, Morocco.</p> Method <p>A cross-sectional quantitative design was employed, involving 451 nursing students recruited through a census approach at a public higher institute in Meknes. Data were collected between January and July 2024 using validated instruments: the Smartphone Addiction Scale – Short Version (SAS-SV) for smartphone addiction, the Pittsburgh Sleep Quality Index (PSQI) for sleep quality, and grade point average (GPA) for academic performance. Structural relationships were tested using partial least squares structural equation modeling (PLS-SEM).</p> Results <p>The prevalence of SA was notably high (81.15%), and 86.467% had a poor SQ. PLS-SEM revealed that SA had a significant direct negative effect on AP (β = -0.460, <i>p</i> &lt; 0.001) and a positive effect on poor SQ score (β = 0.587, <i>p</i> &lt; 0.001). Poor SQ score, in turn, negatively predicted AP (β = -0.227, <i>p</i> &lt; 0.001). SQ partially mediated the relationship between SA and AP, with the indirect effect accounting for 22.4% of the total effect of SA on AP.</p> Conclusion <p>These findings highlight the importance of integrating educational interventions that address both digital behavior and sleep hygiene to improve the academic performance of nursing students. Future research should investigate this dynamic in greater depth across various sociocultural contexts.</p>