A support device adjustable in 3-DOF includes a base, a pitching arm, a rolling arm, a yawing arm, a pitching drive unit, a rolling drive unit, a yawing drive unit, and a controller. The rolling arm rotatably interconnects the pitching arm and the yawing arm. The pitching, rolling, and yawing drive units are configured for automatically driving the pitching, rolling, and yawing arms about pitch, roll, and yaw axes respectively. The roll axis is perpendicular to the pitch and yaw axes. The controller is configured for controlling the pitching, rolling and yawing drive units in response to control inputs. In use, a display panel can be attached to the yawing arm and automatically pitch, roll, and/or yaw by the respective drive units under control of the controller, to achieve an optimum viewing angle.