The art and architecture of Champa, an ancient linguistic and cultural civilization located in modern-day central and southern Vietnam, reflects an interregional artistic koine of Indic culture, a commonality of shared iconography, religion, and the sacred language of Sanskrit. Cham art is related to Hindu and Buddhist art from neighboring Cambodia and most of ancient Southeast Asia. Unique within Southeast Asian art, four extant colossal Cham pedestal-shrines are examined from four archaeological sites of Mỹ Sơn, Trà Kiệu, Đồng Dương, and Vân Trạch Hòa. What objects were placed on the pedestals is not known and interpretations of the imagery carved on the pedestal-shrines are still heavily debated. My dissertation attempts to clarify some of the arguments in current scholarship, holistically across the fields of art history, archaeology, and epigraphical studies, which have been independently analyzed and at times, contradictory. This dissertation explores artistic cultural exchanges and community interactions between Champa and neighboring regions through close analysis of Cham visual culture, including style, scale, iconographies, and patterns. I argue that although the independent entities of Champa were scattered across the coastal areas of modern-day southern Vietnam, the Chams were largely united as visible communities through the combination of colossal image making and written inscriptions. The Chams constructed temple, courtly, and local visual culture to gain economic and social status as itinerant seafarers and trade mediators in the international maritime network of Indian Ocean trade in the 9th-12th centuries. Visual culture became a strategy of economic, religious, and social power for the communities of the Chams.