A wire terminator device for fences and barriers which has two bodies. The first body houses a wire retaining mechanism and the second body stems from the first body and includes an engagement element where the wire is retained in the usage position. The engagement element forming the second body is defined by a through passage in the direction of passage of the wire and a single inlet groove that is oblique with respect to the direction of passage of the wire. The single inlet groove is arranged in the same plane of the direction of passage of the wire in the usage position.