In Study 1, we collected data from a large and diverse international sample of participants in order to create a robust individual differences measure of FoMO. Guided by extant writing about fear of missing out we drafted a pool of statements reflecting FoMO and used a data driven approach to select representative items with the best psychometric properties. Our aim in this first study was to create a sensitive self-report instrument, one that is informative for individuals with low, medium, and high latent levels of fear of missing out, and one that is useful for measuring FoMO in a wide range of research contexts.