According to one embodiment, provide is a liquid crystal display device that suppresses potential change of a common electrode caused by potential change of a signal line. An electrode part is provided on an array substrate so as to surround a display region. A signal line is provided on the array substrate so as to be located in the display region. A passivation film is provided on the array substrate so as to cover at least the signal line and the electrode part. A one-side opening part is provided continuously along an edge part of the display region on the passivation film so that the electrode part is disposed. The common electrode is provided on the array substrate so that a part of the common electrode is located at the one-side opening part and another part of the common electrode is located facing the signal line on the passivation film.