The site of Xtobo was a Preclassic Maya regional center located in the northwest corner of Yucatan, Mexico. The settlement was first occupied during the Middle Preclassic period and saw its peak period of occupation during the late Middle Preclassic and early Late Preclassic. The site appears to have been largely abandoned by the end of the Preclassic period, although a minor reoccupation occurred during the Classic period. Until its documentation in 2002, Xtobo was unknown to archaeologists, and as a result this dissertation represents the first comprehensive study of the settlement The settlement at Xtobo is centered on a well formed plaza flanked by two eight-meter-tall pyramids. Radiating out from the plaza are five causeways, or sacbes, leading to complex structures, most of which appear to have been elite residences. Just to the south of the plaza is a ballcourt believed to date to the Middle Preclassic period. Surrounding the plaza and other central architecture is a dense residential settlement. Analyses of the data recovered from the site suggest it was home to a socially stratified community and likely served as a sociopolitical center for the many other settlements found in the region. Evidence was also recovered demonstrating that the people of Xtobo engaged in long distance trade and interaction with other regions of Mesoamerica The presence of a previously unknown complex Preclassic Maya center in northwest Yucatan has required us to rethink many aspects of Maya cultural development, as well as cultural developments throughout Mesoamerica. While the Middle Preclassic Northern Maya Lowlands were in contact with the Gulf coast Olmec, they did not adopt any of their material cultural forms. The presence of Triadic Group architecture at Xtobo demonstrates ties with other areas of the Maya Lowlands, and yet differentiates the site from its neighboring Northern Maya communities. In addition, the ballcourt at Xtobo is only one of twenty-four examples of Middle Preclassic ballcourt architecture recently found in northwest Yucatan. These ballcourts significantly alter our perceptions of the origins of the Mesoamerican ballgame. These issues are explored throughout this dissertation via the study of the site of Xtobo