A fingerprint sensor includes: a thin film transistor disposed on a substrate; a first insulating layer disposed on the thin film transistor; a first sensing electrode disposed on the first insulating layer and connected to the thin film transistor; a second insulating layer disposed on the first sensing electrode and including an opening exposing the first sensing electrode; a sensing semiconductor layer disposed in the opening of the second insulating layer and on the first sensing electrode, and including an N-type semiconductor layer, an I-type semiconductor layer, and a P-type semiconductor layer, and a second sensing electrode disposed on the sensing semiconductor layer. An upper surface of the sensing semiconductor layer and an upper surface of the second insulating layer are coplanar.