Disclosed are a motor control device capable of accurately estimating a rotor position on the basis of a neutral point potential even when a load acting thereon becomes large, and a brake control device driven by the motor control device. The motor control device 3 is provided with: a three-phase synchronous electric motor 4 equipped with three-phase windings; an inverter 31 connected to the three-phase windings; a control unit 6 for controlling the inverter on the basis of the rotor position of the three-phase synchronous electric motor; and a rotational position estimation means 2 for estimating a rotor position θd on the basis of the neutral point potential Vn of the three-phase windings. The rotational position estimation means estimates the rotor position by selectively using one or more detection values among a plurality of detection values of the neutral point potential in accordance with a previously estimated value of the rotor position and the state of voltage applied to the three-phase windings.