A flexible touch sensor having a visible area and a trace area surrounding the visible area includes a substrate, a touch-sensing layer, and a noise shielding layer. The substrate has a first surface and a second surface facing away from the first surface. The touch-sensing layer is disposed on the first surface of the substrate. The noise shielding layer is disposed on the second surface of the substrate. The noise shielding layer includes a matrix and a plurality of metal nanowires distributed in the matrix.