'Full Stack Feminism in Digital Humanities' (FSFDH) is a collaborative UK-Ireland project between the University of Sussex (UK), Technological University Dublin (Ireland) and Maynooth University (Ireland). Partners include Cambridge Digital Humanities (UK), the Digital Repository of Ireland and the Irish Museum of Modern Art. The project will make the field of Digital Humanities (DH) more inclusive by applying feminist approaches that link cultures, communities, and repositories, and will embed intersectional feminist praxis, as a critical methodological approach, across DH environments. FSFDH will develop and publish an interoperable 'Full Stack Feminist' (FSF) methodology and toolkit, that can be applied by DH communities & organisations, helping to create more inclusive and representative digital cultural heritage. The toolkit is built through an exploration of 3 stacks and work packages: data and archives; infrastructure, tools & code; access, experience, and integration. "Full stack" means we are concerned with issues related to inequalities in DH that span from the infrastructure layer to the representation layer - it reaches, and cuts, across all types of environments. Each stack will be analysed through an intersectional feminist lens to inform the development our open-source toolkit, comprised of various components, including workflows, coding tutorials, a manual, artefacts and a range of published literature. The toolkit will support strategic policy developments and ethics in communities, organisations, and institutions by being made accessible and distributed to digital humanists, social scientists, policymakers, computer scientists, software developers, data journalists, archivists and community archivists, digital artists. Our project will embed social values and humanities methodologies, from back-end development to front-end user interfaces, ensuring feminist inclusionary methodologies are incorporated in the full stack of digital development processes. It is designed to recode DH as a field informed by intersectional feminism and is dedicated to the creation of an inclusive, self-aware, and critically engaged praxis. FSFDH is intersectional, that is, it takes seriously the multiple, overlapping systems of oppression that operate within and across society, and which manifest in our digital environments. FSFDH expands on a framework of engagement seeded in the AHRC-IRC funded network 'Intersections: Feminism, Technology and Digital Humanities' (IFTe). This new project will continue to confront and challenge 'systemic limitations to DH's positive impact on society and culture. Drawing on intersectional feminist theory and practice, its goal is to build an inclusive and responsive DH, able to grapple with complex societal and community needs' (www.ifte.network). It represents a set of feminist approaches that is led by theory, praxis, and action-research. It challenges the perpetuation of algorithmic bias, of gendered and binary information systems, of documenting, digitising, and prioritising the histories and work of "dead white [cis] men". It embeds feminist praxis across and within the development cycle of DH projects, using the "full stack" metaphor to guide interventions in, for example, building inclusive and representative data models, rethinking controlled vocabularies, and critiquing our assumptions of access controls. Digital Humanities has a problem. It is built from inherited heteronormative, gendered, and frequently racist brick and mortar. 'Full Stack Feminism in Digital Humanities' will address this by enhancing and diversifying public access to and engagement with digital cultural heritage and intersectional feminist methods, through the application of FSF and development of the open-source FSF toolkit.