The report outlines the important role UK-based organisations play in delivering programmes and activities designed to tackle issues which limit GESI around the world across sectors of health and well-being, climate change, humanitarian, education, and economic empowerment. The paper is designed to provide a foundational understanding of the issues and problems faced by marginalised members of society and the ways in which these can be tackled and changed with a GESI lens to development. It does this through firstly providing a definition of GESI and a glossary of key terms followed by a chapter which situates GESI across five core global challenge themes including: health, humanitarian, education, climate change, and economic empowerment. The report then offers a proposed framework to support effective implementation of, and impactful change in, GESI. The four key framework pillars are: Strategic Alignment, Inclusive Approach, Operational Rigour, and Measuring Impact of which our members are mapped against in a table. Finally, contributors each provided a short case study of best practice which brings to life the transformational and positive impact of the work they do in GESI.