OBJECTIVES: Transgender issues have become increasingly prominent in sports. However, knowledge of and experience with supporting transgender players across soccer team staff remain unclear. The objectives of this questionnaire-based study were to 1) clarify staff knowledge of transgender-related terminology; and 2) explore soccer team staff's awareness and experience with supporting transgender players. METHODS: A questionnaire was distributed to coaches, physicians, and physical trainers affiliated with soccer teams between 2018 and 2019 to capture 1) participant characteristics (e.g., gender, age, certified license, team categories); 2) their understanding of transgender-related terms, including lesbian, gay, bisexual, and transgender (LGBT) and of the IOC Consensus Meeting on Sex Reassignment and Hyperandrogenism in 2015; 3) their awareness of transgender players; and 4) their experience supporting transgender players. Participants were categorized by age, gender, profession, qualifications, and category of involvement; their understanding and experience were investigated statistically using univariate and multivariate analysis. RESULTS: The 478 respondents included 30 women and 448 men with a mean age of 38 ± 10 years. Of these, 83% understood the term transgender, 75% understood the term LGBT, while only 7% were familiar with the 2015 IOC Consensus Meeting. Physicians reflected more knowledge than coaches and physical trainers (p <0.01). Altogether, 15% had identified transgender players and 1% had experience supporting them. Respondents with certified licenses who worked with women's teams were more likely to recognize transgender players (p <0.01). Four participants (1%) had witnessed transgender players receiving transgender hormone therapy. CONCLUSION: Although most soccer support staff were familiar with transgender terms, many did not have sufficient knowledge of or experience with transgender athletes.