Supercritical Carbon Dioxide (S-CO2) power cycles have gained interest in recent years because they have theoretically been shown to provide higher efficiency than more conventional cycles for heat source temperatures above around 800 K. The main benefit of a S-CO2 power cycles is the low compressor work when it is operated near the critical point, but this provides design challenges. Specifically, properties of S-CO2 vary rapidly, making the computational modelling challenging. The present work presents the aerodynamic design of a radial in-flow turbine for a 10 MWe S-CO2 power cycle. A radial in-flow turbine is designed using literature recommendations and then evaluated with computational fluid dynamics (CFD). The turbine off-design performance is characterized with off-design CFD simulations to create performance maps. Overall, the present work details the aerodynamic design of a radial turbine for operation in a 10 MWe S-CO2 power cycle based on meanline and computational methods.