The concept of a heritage language is broad and highly dependent on context, making it impossible to offer a generalizable account in a chapter such as this. Instead, we present specific contexts to illustrate the concept, focusing principally on the United States but also including other contexts with which we are familiar. The term heritage language emerged in Canada in the late 1970s in the context of the Ontario Heritage Languages Programs (Cummins, 2005). It was used to refer to any language other than English and French, the country’s two official languages, and included languages spoken by Canada’s First Nation people or by its immigrants (Cummins, 1991). In the Australian context, heritage languages were defined as languages other than English (also known as LOTEs; Clyne, 1991). In the United States, the term has been used synonymously with community language, native language, and mother tongue to refer to an immigrant, indigenous, or ancestral language that a speaker has a personal relevance and desire to (re)connect with (Wiley, 2005).