As the world aims to address the UN Sustainable Development Goals (SDGs), it is becoming more urgent for heavy transportation sectors, such as shipping and aviation, to decarbonise in an economically feasible way. This review paper investigates the potential fuels of the future and their capability to mitigate the carbon footprint when other technologies fail to do so. This review looks at the technologies available today, including, primarily, transesterification, hydrocracking, and selective deoxygenation. It also investigates the potential of fish waste from the salmon industry as a fuel blend stock. From this, various kinetic models are investigated to find a suitable base for simulating the production and economics of biodiesel (i.e., fatty acid alkyl esters) and renewable diesel production from fish waste. Whilst most waste-oil-derived biofuels are traditionally produced using transesterification, hydrotreating looks to be a promising method to produce drop-in biofuels, which can be blended with conventional petroleum fuels without any volume percentage limitation. Using hydrotreatment, it is possible to produce renewable diesel in a few steps, and the final liquid product mixture includes paraffins, i.e., linear, branched, and cyclo-alkanes, with fuel properties in compliance with international fuel standards. There is a wide range of theoretical models based on the hydrodeoxygenation of fatty acids as well as a clear economic analysis that a model could be based on.