Czech Americans, known in the 19th and early 20th century as Bohemian Americans, are citizens of the United States whose ancestry is wholly or partly originate from the Czech lands, a term which refers to the majority of the traditional lands of the Bohemian Crown, namely Bohemia, Moravia and Czech Silesia. These lands over time have been governed by a variety of states, including the Kingdom of Bohemia, the Austrian Empire, Czechoslovakia, and the Czech Republic also known by its short-form name, Czechia. Germans from the Czech lands who emigrated to the United States are usually identified as German Americans, or, more specifically, as Americans of German Bohemian descent. According to the 2000 U.S. census, there are 1,262,527 Americans of full or partial Czech descent, in addition to 441,403 persons who list their ancestry as Czechoslovak. Historical information about Czechs in America is available thanks to people such as Mila Rechcigl.

Czech, historically also known as Bohemian, is a West Slavic language of the Czech–Slovak group, written in Latin script. Spoken by over 10 million people, it serves as the official language of the Czech Republic. Czech is closely related to Slovak, to the point of high mutual intelligibility, as well as to Polish to a lesser degree. Czech is a fusional language with a rich system of morphology and relatively flexible word order. Its vocabulary has been extensively influenced by Latin and German.