A locking mechanism for a console device, which restricts a console armrest of the console device disposed between a driver seat and a passenger seat inside a vehicle, includes a housing mounted on a front surface of a console box of the console device, a pivoting lever pivotably coupled to an inner surface of the housing, a slider pivotably coupled to an upper body of the pivoting lever, an inertial member interlocking portion coupled to a lower body of the pivoting lever, an inertial member seating portion which is mounted on the housing and on which an inertial member is seated, and the inertial member provided between the inertial member interlocking portion and the inertial member seating portion and configured to operate the inertial member interlocking portion when a collision of the vehicle occurs.