This study explores how Black girls express their "Black girl imagination" while participating in a critical, informal science learning program, Empowering Girls Through Art & Science, designed to prioritize the positive visibility of Black girls and promote the critical exploration of scientific histories. The goal of the research was to identify ways Black girls actualize their "Black girl imaginations" through expressions of childhood, criticality, and creativity. Three questions structured the study: (1) How do adolescent Black girls express their "Black girl imaginations" when participating in a critical, informal science learning space designed with them in mind? (2) What do their expressions of "Black girl imagination" reveal about their articulations of self? (3) What do their expressions of "Black girl imagination" reveal about their meaning making in science? The framework for the study is constructed from three theoretical perspectives - Black girlhood studies, critical race-informed science education, and afrofuturism. I use Black girlhood studies to acknowledge that Black girls occupy unique intersections of identities, distinct from Black women, which yield a unique criticality and creativity. I use two tenets of critical race theory - colorblind racism and whiteness as property - to acknowledge the ways Western, Eurocentric approaches to science are exclusionary, and, in response, I articulate five shifts for revolutionizing science education to center Black girls. I use afrofuturism to legitimize the Black imagination, expand what is considered scientific, and redefine how time is conceptualized. The methodology of portraiture is used to understand how Black girls question the status quo, take critical stances against injustice, and create change where their voices are systemically excluded. Findings are presented as visual and narrative portraits of three focal participants. I draw on program applications, semi-structured interviews, focus groups, video diaries, participants' artistic expressions, and researcher memos. Analysis of the data demonstrates that these Black girls are thinking deeply and critically about the world. Offering spaces where Black girls can authentically express their childhoodness, share their critical perspectives, and communicate creatively allows for the development of counterstories of Black girls in science learning environments. These counterstories in the form of portraits present three distinct representations of Black girls in science.This dissertation offers a layered counterstory - a combination of multiple counterstories that work together to center marginalized stories and ways of storytelling across a research process - that allow for the elevation of Black girl meaning making. This study has important implications for stakeholders in science education. This study reveals to classroom teachers that children can navigate across multiple epistemologies of science and hold the capacity to grapple with science from a variety of perspectives. It confirms that teacher educators must prioritize moments to unpack preservice teacher bias, explore Black, Brown, and Indigenous scientific histories, and practice embedding and facilitating opportunities to learn. Science education scholars should consider the layered counterstory when seeking to center marginalized voices and more opportunities to elevate Black girl meaning making is critical. Narratives that illuminate Black girls' beauty and brilliance, told from their perspectives, deserve to be centered and celebrated. My hope is that by elevating Black girl voice in this dissertation, the fields of science education take the brilliance and beauty of Black girls as axiomatic and begin to redefine the structures that currently guide the disciplines to move Black girls from the margins of science learning to the center. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]