An organic light emitting display device has a display panel including a first subpixel, a second subpixel, a data line, and sensing lines. The sensing lines may include a vertical sensing line and a horizontal sensing line connected to the vertical sensing line. The horizontal sensing line may be formed of a source/drain metal layer present on the first substrate, and one portion thereof connected to a first electrode of a sensing transistor of the first subpixel and the other portion thereof connected to a first electrode of a sensing transistor of the second subpixel may be positioned in a region intersecting with the data line, and electrically connected by a connection electrode formed of an insulated light blocking layer below the source/drain metal layer present on the first substrate.