Fullagar, HHK, Harper, LD, Govus, A, McCunn, R, Eisenmann, J, and McCall, A. Practitioner perceptions of evidence-based practice in elite sport in the United States of America. J Strength Cond Res XX(X): 000-000, 2019-Practitioners' perceptions regarding the use and effectiveness of research evidence in sport is not well understood. The purpose of the present study was to examine practitioners' perceptions around the use, implementation, and barriers to evidence-based practice (EBP) in sport science in the United States of America (USA). A survey (28 items) was completed by 67 full-time staff who were a physical performance team member employed by universities or professional sporting organizations in the USA. Questions included the use of research, contribution of research areas, barriers to accessing and implementing EBP, and methods of feedback to the coach and players. All respondents (100%) stated they used research evidence in their performance/training program, ranking research as contributing most (largest contribution = 1 to smallest contribution = 4) to individualized preparation or recovery recommendations (1.98 ± 1.02). The top 3 preferred sources of information were "peer-reviewed research" (100% of respondents), "conferences/seminars" (76%), and "practitioners within your sport" (63%). Commonly reported perceived barriers between accessing and implementing research were "lack of staff" (accessing = 33%, implementing = 46%) "time" (accessing = 38%, implementing = 48%) and nonapplicable research (accessing = 33%, implementing = 37%), whereas "poor player compliance" was a clear barrier to implementing EBP (56%). Practitioners most preferred, and actual, method of feedback for coaching staff (87% for both) and players (94 and 95%, respectively) was "informal conversations/speaking." Improved access to educational and financial resources, increased integration of staff in coach settings and understanding of player/coach contexts may help to alleviate barriers to EBP.