This paper focuses on the Sicilian city of Himera and the account Thucydides provides about it concerning its foundation and development. Specifically, Thucydides’ comment regarding the “mixed-dialect” of Himera and its Chalcidian nomima is addressed in the context of Hellenic language and ethnicity during the Archaic period. Through the use of epigraphic and numismatic evidence, as well as the language of Stesichorus, I examine the possible dialectic markers of ethnic identification at Himera and make observations regarding their significance. The purpose of doing so is to both test the validity of Thucydides’ account, as well as evaluate the ways in which nomimamediates ethnic divisions in multi-ethnic cities. Through the examination of the evidence I argue that Thucydides’ claim concerning the Chalcidian nomima of the city is supported, but there is little evidence to support his claim of a mixed-dialect at Himera. This conclusion does not, however, prove the absence of a mixed-dialect at Himera. Rather, it stresses the strength of nomima in defining the ethnic designation of a multi-ethnic city, as seen through material and literary evidence.