According to one embodiment, a disk device includes a recording medium, a suspension, a magnetic head, an actuator, a circuit board, an FPC, a preamplifier, and an actuator driver. The magnetic head and the actuator are mounted on the suspension. The circuit board includes a control circuit. The FPC is connected to the suspension and the circuit board. The preamplifier is mounted on the FPC, outputs a write signal, to the magnetic head, corresponding to information to be written to the recording medium by the magnetic head, and receives, from the magnetic head, a read signal corresponding to information read from the recording medium by the magnetic head. The actuator driver is mounted apart from the preamplifier on the FPC, the actuator driver that outputs a drive signal for driving the actuator to the actuator.