The Chickasaws are one of the Five Tribes removed by the U.S. government to Indian Territory (now Oklahoma) more than 150 years ago from their homelands in the southeastern United States. Most speakers of the Chickasaw language now live in the Chickasaw Nation in south-central Oklahoma. Although there are fewer than one hundred fluent speakers today, the tribe has a language program designed to revitalize and perpetuate the language. This first scholarly dictionary of the Chickasaw language contains a Chickasaw-English section with approximately 12,000 main entries, secondary entries, and cross-references; an English-Chickasaw index; and an extensive introductory section describing the structure of Chickasaw words. The dictionary uses a new spelling system that represents tonal accent and the glottal stop, neither of which is shown in any previous dictionary of either Chickasaw or the closely related Muskogean language, Choctaw. In addition, vowel and consonant length, vowel nasalization, and other important distinctions are given. Grammatical information is also provided. The dictionary is the product of a seventeen-year collaboration between Pamela Munro and Catherine Willmond. They have consulted over forty other Chickasaw speakers in Oklahoma to collect variant forms of words, which are also listed in the dictionary.