A new generation of double wythe insulated sandwich wall panels is being developed at Queen’s University for the precast industry through the Canadian Precast/Prestressed Concrete Institute (CPCI). The new design uses very thin ultra-high-performance fiber-reinforced concrete (UHPFRC) wythes of 15–38 mm, which enables a remarkable reduction in self-weight and savings in transportation and craning operations. However, the challenge with thin walls is securing enough embedment for connections. This study investigates the pull-out strength of a variety of connection configurations and varies the wythe thickness, polymeric fiber ratio in the mix, connector diameter, embedment depth, back cover, and end bearing area. It was concluded that current equations overestimated the capacity of cast-in connectors in thin UHPFRC panels. As a result, a multiple linear regression analysis is carried out to develop design expressions for these connections.