Abstract: A host vehicle position estimation device includes an object determination unit configured to determine whether or not a planar object is included in a captured image, on which a host vehicle travels, a center point information acquisition unit configured to, when the planar object is included in the captured image, acquire center point information of the planar object including at least one of longitudinal center coordinate and lateral center coordinate of the planar object in the captured image, a longitudinal distance calculation unit configured to calculate a longitudinal distance as a distance between the host vehicle and the planar object in a front-rear direction of the host vehicle, and a host vehicle position estimation unit configured to estimate a host vehicle position using the positional information of the planar object on the map and the longitudinal distance.