In the last several decades in the United States, university athletic departments and professional sport teams began hiring sport scientists to support team operations. Many variations in sport science–related job titles and a variety of duties are apparent across the industry internationally. Therefore, the aims of this article were to (a) define sport scientist roles because they may be positioned in U.S. sport organizations, (b) demonstrate potential levels of application, (c) demonstrate how a sport science program helps establish a standard of care for the athlete, and (d) highlight overseas practices that establish professional competency for those in sport scientist roles. This discussion may be used to optimize organizational structures, enhance organizational dynamics within sport organizations, leagues, and systems, and used to develop, refine, or support certification and training programs in the United States. In addition to the discussion in this article, several job descriptions are provided as Supplemental Digital Content, http://links.lww. com/SCJ/A347. These resources may help decision makers construct job descriptions for their organizations.