This qualitative single-case study explores how culturally responsive practices are enacted within Net Worth, a sport-based youth development organization serving Black youth in a marginalized community in Florida, United States. Centered around an out-of-school-time tennis program, the study examines the mindsets and experiences of administrators, staff, and volunteers engaged in promoting positive youth development through a non-traditional sport. Data sources included 53 field observations, 29 semi-structured interviews, archival documents, and organizational artifacts. Using deductive thematic analysis, the study identified patterns and themes of cultural responsiveness, highlighting both effective practices and areas needing improvement. Findings contribute to a deeper understanding of how cultural responsiveness operates in sport-based youth development settings and offer implications for enhancing inclusive and contextually relevant programming.