A gaze detection apparatus includes a light source configured to irradiate an eyeball of a subject with detection light, a position detection unit configured to detect positions of pupil centers indicating centers of pupils of right and left respective eyeballs and positions of corneal reflection centers indicating centers of corneal reflexes of the right and left respective eyeballs from an image of the eyeball irradiated with the detection light, a curvature radius calculation unit configured to calculate corneal curvature radii of the right and left respective eyeballs from a position of the light source and the positions of the corneal reflection centers, a gaze detection unit configured to detect gaze directions of the right and left respective eyeballs from the positions of the pupil centers and the corneal curvature radii, a viewpoint detection unit, an output control unit, and a determination unit.