["Journal of Organizational Behavior, Volume 47, Issue 4, Page 595-626, May 2026. ", "\nABSTRACT\nTo better understand how coworkers socialize for fun, this multistudy research builds on prior conceptualizations to develop and validate a more conceptually precise measure of coworker socializing for fun. We introduce the Multidimensional Coworker Socializing for Fun Scale (MCSFS), conceptualized as a higher‐order construct reflected in three first‐order dimensions—friendly conversations, playful interactions, and gathering socially. Drawing on data from eight diverse samples of employees from multiple industries (total N = 1535) and four phases of scale development, results provide evidence of content, convergent, and discriminant validity. Confirmatory factor analyses support the hierarchical structure of the measure. The MCSFS also demonstrates nomological validity via positive relationships with theoretically relevant relational, attitudinal, and well‐being outcomes, with dimension‐level analyses indicating meaningful differences across the three dimensions of coworker socializing for fun.\n"]