Due to limited research on Black girls in science education, this study focuses on the forms of capital Black girls cultivated through their participation in a community-based STEM after-school program. The study drew from the interviews and a focus group session of 10 Black girls and investigated their formal and informal experiences in science. Using intersectionality and community cultural wealth as theoretical perspectives, findings revealed that multiple forms of capital (aspirational, social, navigational, and familial) were fostered and interconnected throughout the program. The intersections of race and gender were also prominent contributions to the multidimensional, nuanced ways Black girls experience and flourish in STEM education. Implications and recommendations for future research on Black girls in science are discussed.