The life and contribution of Charlie Seashore are at the core of the organization development (OD) discipline and practice. Charlie embodied characteristics of the consummate OD scholar-practitioner, and he serves as a role model that many OD practitioners and budding professionals attempt to emulate. This article shares the story of his life, describing family connections to Kurt Lewin, his childhood and formative life experiences, his teaching and mentoring OD professionals, and his intellectual contributions to the field of OD. The article suggests that Charlie Seashore has been a key link in the trajectory of OD from its formative beginnings at NTL (National Training Laboratories) Institute to its present role in our society and throughout the world.