Leadership behaviors are an important aspect of athletic training and are needed within all allied health care disciples. A two-phase, exploratory, non-experimental research study using a Delphi technique and a randomly selected sample of athletic trainers (n = 161) was conducted to determine leadership competencies perceived to be important for athletic training practice and education. The Delphi technique (phase one) resulted in the Leadership Development in Athletic Training instrument (LDAT). In the national survey (phase two), respondents used the LDAT to rate the importance of leadership competencies for athletic training practice and for athletic training education. Coefficient alphas ranged from α = 0.83 to 0.97 and provided satisfactory estimates of internal consistency. Concurrent, construct, and convergent validity were established. Forty-nine leadership competencies were rated important for practice and 48 for education (M = 1.5, p ≤ 0.001). Exploratory factor analysis revealed that leadership competencies were organized by four constructs (with six emphases): 1) personality characteristics, 2) diagnosing context and people skills, 3) communication and initiative, and 4) strategic thinking. Repeated measures ANOVA with Sidak post-hoc adjustments indicated each leadership construct significantly increased in importance as the level of the ATEP progressed.