This paper investigates the aerodynamic performance of the three-dimensional lifting supersonic biplane and its sonic boom. Although the Busemann biplane is known to cancel the wave drag, it does not produce lift, either. A few decades later, the supersonic biplane airfoils with lift were reported. This paper extends their ideas to the three-dimensional biplane. The aerodynamic performance was revealed by using computational fluid dynamics. The possibility of sonic boom mitigation due to shock wave interaction was demonstrated.