The present research attempts to investigate an intermediating process that influences an association between transformational leadership and innovative behavior. Previous studies have mainly focused on the intrapsychic traits of individual employees (e.g., intrinsic motivation and psychological empowerment) as an important mediator to explain the enhancing effect of transformational leadership on employee's creativity. Yet, given that many interactions among employees in an organization tend to occur in the form of 'interpersons', the importance of interpersonal relationship-based traits has received relatively less attention from leadership scholars. Based on the context-attitude-behavior framework, we posit that transformational leadership enhances innovative behavior by boosting the level of employees' forgiveness which is an interpersonal relationship-based trait among employees. We conducted structural equation modeling analysis with a survey from 374 employees in South Korea. The result demonstrated that forgiveness partially mediates the influence of transformational leadership on innovative behavior. We believe that our finding may contribute to expanding transformational leadership and positive organizational scholarship literature by identifying a new path that transformational leadership increases innovative behavior. The theoretical and practical implications, limitations of this study, and suggestions for future research are discussed.