Abstract: The present invention provides a welding torch weaving device having a first link with an elongated slot and driven by a drive source to make an arc shaped movement at one end thereof, a first movable shaft fitted or secured within the elongated slot in the first link, a second link having one end thereof pivoted in place on the first link and having a second elongated slot, a second movable shaft fitted within the second elongated slot in the second link, a third link having one end thereof pivoted in place on the other end of the second link and a fourth link having one end thereof pivoted in place on the other end of the third link and the other end thereof pivoted on a fixed pivot shaft. A weaving arm is disposed in place on the third link for mounting a welding torch.