An automatic pilot device for a rotary wing aircraft and rotary wing aircraft comprising such device are disclosed. In one aspect, the automatic pilot device comprises at least one automatic pilot assembly including at least two primary actuators, at least one or each of the primary actuators incorporating an electronic computation unit. The computation unit is configured to: communicate with a measuring system configured to generate measuring signals and/or a cockpit configured to generate control signals as a function of the actions by a crew, and compute, as a function of the measuring signals and/or control signals, a piloting setpoint for the primary actuator incorporating the computation unit and/or a piloting setpoint for at least one or each other primary actuator of the automatic pilot assembly, for the piloting of the aircraft by the automatic pilot device.