A self-localization estimation device includes: a map-information acquisition unit that acquires map information including lane information for specifying lanes in which vehicles are enabled to travel; a position calculation unit that calculates an own-vehicle absolute position being an absolute position of an own vehicle in response to navigation signals received from a plurality of navigation satellites, the position calculation unit including a self-location measurement unit, a vehicle-momentum measurement unit, and dead reckoning unit; and a position estimation unit that estimates, based on the map information and the own-vehicle absolute position, a corrected own-vehicle position being a corrected position of the own vehicle. The position estimation unit estimates the corrected own-vehicle position by superimposing a reliability of the map information and a reliability of the own-vehicle absolute position on each other.