With the global increase in passenger traffic and growing popularity of long-haul routes over the Asia Pacific region and Atlantic Ocean, the possibility for hypersonic transport could become an attractive option to reduce flight time over long distance from 16-20 hours down to around 4-5 hours. In this thesis, a Multi-Disciplinary Optimisation platform has been developed to allow for the optimal sizing of hypersonic transport vehicles using vehicle take-off mass as the performance indicator subjected to fuel volume and payload height constrains. The current platform is applied to the LAPCAT A2 hypersonic long-range transport configuration by Reaction Engines, to determine the impact of range and cruise Mach number on the design of hypersonic aircraft. Results show that the optimal shape is greatly dependent on the aircraft range and fuel volume constraint. Additionally, the optimum hypersonic cruise Mach number is dictated by a trade-off between mission time, engine efficiency and Thermal Protection System mass.