Background/Significance: Script concordance tests, based on script theory, have been proposed to objectively measure clinical reasoning in medical professionals. As the result of much research, best practices exist guiding the construction of script concordance tests and have been implemented within multiple professions. However, use of a script concordance test as a measure of clinical reasoning in athletic training has not yet been investigated. Purpose: The purpose of this study was to systematically develop a script concordance test specific to athletic training, demonstrating validity and internal reliability. Methods: Five content experts responded to an initial survey to delineate a test blueprint and a subsequent survey to establish face validity of the resultant script concordance test. Twenty expert clinicians then completed the tests. Analyses of validity and internal reliability were calculated from the expert panelist responses to create a final optimized version of the test. Results: Item level and scale level content validity indices of 1.0 were both established for a novel script concordance test in athletic training. A 100-item test displayed a Cronbach’s alpha value of .48. Item analysis and subsequent removal of all performing items resulted in a 75-item test with a Cronbach’s alpha value of .73. A further item analysis with subsequent removal of worst performing vignettes resulted in a 60-item final version of the script concordance test possessing a Cronbach’s alpha value of .77. Conclusions: Through purposeful selection of content experts, a novel script concordance test measuring clinical reasoning in athletic training was developed, displaying face validity. Purposeful selection of a reference expert panel resulted in the script concordance test demonstrating internal consistency reliability. The validated script concordance test poses implications for further research in clinical reasoning specific to the athletic training profession.