People's beliefs about emotions may be grouped into two main categories: beliefs about the controllability of emotions and beliefs about the usefulness of emotions. These beliefs influence emotion regulation efforts and mental health, so the assessment of these beliefs is important. However, few psychometric measures are available, particularly for assessing the usefulness dimension. In this study (N = 161), we address this issue by developing and conducting an initial validation of a 16-item self-report measure called the Emotion Beliefs Questionnaire (EBQ). Confirmatory factor analyses found its structure to consist of three first-order factors: a controllability factor spanning both negatively and positively valenced emotions (General-Controllability), and two valence-specific usefulness factors (Negative-Usefulness, Positive-Usefulness). All first-order factors also loaded together on a higher-order factor, representing an overall maladaptive beliefs about emotions construct. All subscale and composite scores had good levels of internal consistency. Correlational and regression analyses found that EBQ scores related in expected ways with other measures, and were significant predictors of emotion regulation abilities and psychopathology. We conclude that the beliefs about emotions construct is multidimensional, and the EBQ appears to be a promising new tool to assess it.