Many people desire work that matters to others and society. This study reports the development and validation of the Work Mattering Scale (WMS), which measures work mattering with two dimensions, that is, societal mattering and interpersonal mattering. Phase I utilized a review of the scholarly literature, in-depth interviews, and expert feedback to formulate 45 items. In Phase II, with a sample of 299 working adults in the United States, exploratory factor analyses were employed and produced a two-factor model with 10 items. In Phase III, with another sample of 251 working adults, confirmatory factor analyses were conducted to test the initial structure specified in Phase II. In Phase IV, the construct validity was examined by correlations and factor analysis among the total and subscale scores with existing measures. In Phase V, 4-week test–retest reliability was calculated. Results provided support for the reliability and validity of the WMS.