This paper describes a majority logic gate circuit on a "single-dopant" device. The single-dopant device that has been receiving increasing attention in recent years is one of atomic scale solid-state device and can be a practical platform for a single-electron circuit. We here aim to fabricate actual single-dopant majority logic circuits with deterministic doping method. For this, we design a possible circuit on the device and test its operation by Monte Carlo simulation as a first step of this study. As results, we confirmed correct circuit operation and found that the device will have thermal-noise- and device-parameter-fluctuation-harnessing abilities. We believe that we will succeed to fabricate practical the single-dopant majority logic gate circuit in near future.