Provided are a navigation device and a navigation method capable of reducing the size and the cost of an endoscope, and an endoscope system including the navigation device. The navigation device includes a magnetic field generation control unit that causes magnetic fields to be generated at different timings from a plurality of magnetic field generation units that generate the magnetic fields at mutually different positions; an image signal acquisition unit that acquires, from the endoscope, an added image signal obtained by adding specification information for specifying the magnetic field generation units generating the magnetic fields and magnetic field detection results of the respective magnetic field detection units to an image signal output from an imaging element; and a position detection unit that detects positions of the respective magnetic field detection units on the basis of the specification information and the magnetic field detection results that are added to the added image signal acquired by the image signal acquisition unit.