This study was carried out jointly by the University of Birmingham and the British Geological Survey. The report addresses the feasibility of using novel quantum-technology-based gravity sensors to monitor underground CO2 storage. Of particular interest is the applicability to upcoming near-surface leak monitoring trials that the British Geological Survey will be conducting at its test site. UKCCSRC Flexible Funding 2021: Feasibility study into Quantum Technology based Gravity Sensing for CCS