The aim of this research is to assign the provenance of marble samples uncovered from the extra-mural Byzantine Church of Udhruh (Augustopolis), south Jordan. The church is a three-nave basilica that most probably was built in the fifth century CE. In later expansion phases, it was remodeled by the addition of two side chapels and several rooms. The research investigated the physical, mineralogical, and isotopic properties of twenty-four marble samples of different functions using naked eyes, lenses, and multiple analytical techniques including optical microscopy, mass spectrometry, and X-ray diffraction. The results showed that the architectural elements were made of the gray calcitic Proconnesus-1 marble (Marmara, Turkey); while the four fonts or basins were carved out of the beige dolomitic Thasos-3 marble (Thasos Island, Cape Vathy, Greece); and the small squared column of unknown function was carved out of the fine-grained white calcitic Penteli marble (Mount Pentelikon, Attica, Greece). The results indicate that the most popular supply of the ecclesial marble to the south (and north) Jordan during the Byzantine period was the gray Proconnesus-1. The use of white Penteli and Thasos-3 marbles were limited to ritual elements.