Decarbonisation of transport is essential to achieve the UK's stated goal of achieving net-zero greenhouse gas emissions. Synthetic fuels, which include a range of biomass-derived fuels and those produced by combining renewable hydrogen and captured CO2, are expected play a crucial role in reducing emissions in shipping and aviation sectors, and potentially in passenger road transport as well. In the UK context, the rapid expansion of cost-effective offshore wind and the deployment of carbon capture technologies will provide the necessary resources that could underpin a domestic fuel production industry. This PhD project will develop novel life cycle assessment and techno-economic approaches to assess the potential for synthetic production within the UK and their use in the light duty vehicle fleet, and extend findings to the heavy-duty road fleet, rail, marine, and/or aviation sectors. The comprehensive approach undertaken will consider the current and future mix of hydrogen production routes and CO2 sources; anticipated developments in fuel production processes; and suitability for direct substitution for conventional fuels in transport applications.