This study examines 2,000 years of marine trade to the ancient Maya site of Ceibal, Guatemala. Located almost 150 kilometers from the nearest coast in Belize, Ceibal was a large community spanning the Middle Preclassic through early Postclassic periods (1000 b.c.–a.d. 1200). It therefore provides an excellent opportunity to assess the marine resources imported through the southern Maya lowlands over many centuries, offering insight into trade networks, uses of shell ornaments, religious beliefs and rituals, and other activities involving marine species. The study compares marine invertebrate data from Ceibal to a neighboring subordinate community, Caobal, as well as data previously reported from sites in the southern Mesoamerican lowlands, in order to understand regional sociocultural and trade connections over time. The majority of Ceibal's marine taxa are Atlantic species and reflect shell trends observed elsewhere in Guatemala and Belize, suggesting strong ties to trade networks eastward to the coast that lasted many centuries.