Sandwich wall panels (SWPs) have been used in the precast industry for decades for their durability, quick installation, and thermal efficiency. Sandwich Wall Panels consist of two layers of reinforced concrete (exterior wythe known as the façade wythe and interior wythe known as the structural wythe) with an embedded layer of thermal insulation. The two concrete wythes are interconnected using shear connectors, which enables the transformation of shear forces across the wythes. Incorporating Glass Fiber-Reinforced Polymer (GFRP) shear connectors represents a significant advancement in SWP technology. These connectors enhance the composite structural performance and maintain thermal efficiency by effectively mitigating thermal bridging. Ultra High-Performance Concrete (UHPC) is an advanced construction material characterized by its exceptionally high strength and durability, achieved through a dense microstructure and the inclusion of fibres to enhance its mechanical properties. The emergence of UHPC in SWPs can reduce the thickness of these panels, thus reducing the overall weight and diminishing the need for longitudinal and transverse reinforcements. Engineers require specific design values from the connectors’ manufacturer to design SWPs. Although previous research has focused on double shear tests to determine the shear capacity of various commercially available connectors, these studies have been limited to normal-strength concrete. There has been no specific examination of the mechanical properties of shear connectors in UHPC. Therefore, this paper aims to determine the shear and tension capacity of the GFRP shear connectors. Furthermore, the stiffness value is calculated using the load-deflection relationship obtained.