•A path model examined how locus of control (LoC) is related to cell phone use and behavioral outcomes.•Behavioral outcomes include sleep quality, academic performance and subjective well-being.•LoC is not related to total daily cell phone use, but to use at inopportune times and circumstances.•Greater external LoC: less control of use at bedtime, in class, and while studying.•More inopportune use: lower in sleep quality, academic performance and subjective well-being. This study centers on the following hypothesis: that individuals with an external locus of control, in comparison to individuals with an internal locus of control, have less control over their cell phone use (i.e., more likely to use at bedtime; more likely to use in class and while studying) and are consequently more vulnerable to the negative outcomes associated with excessive cell phone use (i.e., poor sleep quality, reduced academic performance, and reduced subjective well-being). Methods: Undergraduate college students (N=516) participated in the study by completing validated surveys assessing their cell phone use, locus of control, sleep quality, academic performance, and subjective well-being. A path model was used to examine how locus of control relates to students’ cell phone use and the key outcome variables. Results: The model exhibited reasonable model fit with all paths being statistically significant and in the hypothesized direction. Conclusion: By enabling an individual to better control cell phone use at inopportune times, a greater internal locus of control may mitigate some of the negative outcomes associated with high frequency cell phone use; conversely, an individual with a greater external locus of control may have difficulty controlling use at inopportune times and the negative effects associated with high frequency use may be exacerbated.