This article examines sign languages that belong to a complex of indigenous sign languages in Mesoamerica that K'iche'an Maya people of Guatemala refer to collectively as Meemul Tziij. It explains the relationship between the Meemul Tziij variety of the Yukatek Maya village of Chican (state of Yucatán, Mexico) and the hitherto undescribed Meemul Tziij variety used six hundred kilometers away in the K'ichee' Maya township of Nahualá (department of Sololá, Guatemala). Consistent with indigenous beliefs, these languages are distinct and unrelated to the European and Euramerican sign languages. The sign language varieties in question likely belong to a single ancient language family derived from an ancient signed lingua franca, given the fact that indigenous communities scattered across Mesoamerica still use the languages. The conclusion summarizes findings, discusses implications for Mesoamerican history, and suggests directions for future research.