Emotion regulation has been proposed as a mechanism for the development of problematic smartphone use. In addition to examining the relationship between emotional regulation difficulties and problematic smartphone use, the current study sought to be the first to examine the relationship between subscales of emotion regulation difficulties and problematic smartphone use. It also sought to determine whether emotion regulation difficulties provide incremental prediction of problematic smartphone use over and above personality. Participants were 692 Australian university students (81% female; age in years M = 25.23, SD = 7.48). They completed a measure of problematic smartphone use, the Difficulties in Emotion Regulation Scale, and a measure of Big Five personality (IPIP 120). Overall emotion regulation difficulties (r = .40) and impulse control difficulties (r = .42) were moderately associated with problematic smartphone use, as were the Big Five factors of neuroticism (r = .43) and conscientiousness (r = -.38). Although emotion regulation difficulties predicted problematic smartphone use, they did not provide incremental prediction over and above the Big Five. Findings indicate that personality is a robust predictor of problematic smartphone use. Emotion regulation difficulties, such as impulsivity, offer insights into the specific ways that personality is expressed in problematic smartphone use.