This article summarizes the impact of Theodore Millon's work on the disciplines of health psychology and behavioral medicine over the past 5 decades spanning from the late 1960s to present. The article is written from my perspectives as a graduate student mentored by Millon on through my faculty career as a collaborator in test construction and empirical validation research. Several of the most recent entries in this summary reflect projects that were ongoing at the time of his passing, revealing the innovation and visionary spirit that he demonstrated up until the end of his life. Considering that this summary is restricted to Millon's contributions to the disciplines of health psychology and behavioral medicine, this work comprises only a small portion of his larger contribution to the field of psychology and the areas of personality theory and psychological assessment more broadly.