(1) Organization development (OD) is defined as a planned, organization-wide effort to increase effectiveness and health through interventions that change beliefs, attitudes, values, and structure. (2) OD draws on behavioral science and involves collaboration, long-term planning, systems thinking, and evidence-based change. (3) Key aspects of OD include addressing organization-wide issues, using change agents, taking action, emphasizing performance and learning, and having a humanistic, problem-solving orientation.