This chapter reviews the “classic expertise approach,” which is defined as the research line starting with Simon and Chase’s (1973) chunking theory, culminating in the early 1980s, and dominating expertise research until the 1990s. After briefly reviewing early research (e.g., Binet, 1894b; De Groot, 1946), an overview of the key experimental and theoretical results obtained with this approach is provided. The chapter also discusses influential theories stemming from the classic approach, such as long-term working memory (Ericsson & Kintsch, 1995), EPAM-IV (Richman, Staszewski, & Simon, 1995) and template theory (Gobet & Simon, 1996). The discussion highlights the defining research methods and theoretical assumptions of this approach. Directions of research for the future are discussed, based on the characteristics that made the classic approach highly successful.