The invention provides an engine start control system and a vehicle, which can assist in driving an engine and improving fuel economy. The internal combustion engine start control system (3) includes: an electric motor (20) configured to rotate a crankshaft (10); an electric motor control unit (24) configured to control an output of the electric motor; and an ECU (2) configured to perform a fuel injection control. The electric motor includes a first circuit mode and a second circuit mode whose output torques are different from each other. The electric motor control unit is configured to drive the electric motor by using the first circuit mode until a motor speed reaches a first rotational speed and to drive the electric motor by switching from the first circuit mode to the second circuit mode until the motor rotational speed reaches a second rotational speed which is higher than the first rotational speed when the engine speed exceeds the first rotational speed. The ECU is configured to start the fuel injection control when the engine speed is equal to or higher than a third rotational speed which is higher than the first rotational speed and lower than the second rotational speed.