Background: This study aimed to: (a) explore differences in the prevalence of nomophobia and smartphone addiction (SA) from pre- to during COVID-19; (b) identify students' self-reported changes in smartphone reliance and screen time during COVID-19; and (c) examine whether self-perceived changes in smartphone usage predicted nomophobia and SA scores. Methods: Scores on the Nomophobia Questionnaire and Smartphone Addiction Scale between two surveys administered at two timepoints were compared: Sample 1 (September 2019-January 2020; N = 878) and Sample 2 (May-June 2020; N = 258). Results: No significant differences were found between samples on nomophobia or SA. Nearly all of Sample 2 reported using some type of app "more," using their smartphone "a little more," and "about the same" perceived smartphone reliance during COVID-19. Increased screen time, smartphone reliance, and social media significantly predicted nomophobia and SA. Conclusion: COVID-19 does not appear to have exacerbated the prevalence of nomophobia or SA.