An improved clip for supporting standing seam roofing panels on purlins or joists is disclosed. When used, this unique clip will not only support a standing seam, formed by two adjacent, connecting roofing panels, on a purlin, but will also accommodate both rotational and translational movement of the panels relative to the purlin. The disclosed clip is formed with several basic components: a base which is attachable to a purlin or joist; a middle piece which is capable of rotational displacement relative to the base; and a moveable top piece which is capable of translational, sliding movement relative to the middle piece. When in use, the top piece of the clip will coact with the interior of the standing seam to form a substantially tight, non-moving union with the seam. The base of the clip will be attached to the joist or purlin to support the roofing panels. When so situated, the novel clip according to the present invention may accommodate both translational, longitudinal movement of the roofing panels (which may be caused by thermal expansion or contraction of the panels), and rotational movement of the roofing panels (which may be caused by the application of live or dead loads on the panels), relative to the purlin. Further, a clip according to the present invention may also be used to attach standing seam roofing panels to joists or purlins which are not level, which have flanges out of square with the web of the purlin, or which are misaligned with the remaining purlins.