The "Czech lands" (Czech: České země) is an auxiliary term used mainly to describe the combination of Bohemia, Moravia and Czech Silesia. Today, those three historic provinces compose the Czech Republic. The Czech lands have been settled by Slavic people since the fifth century.

The term "Czech lands" has been used to describe different things by different people. Some sources use the term to mean any territory under the Bohemian (or "Czech") crown. This would include territories like Lusatia and Brandenburg (now in Germany) and the balance of Silesia, all of which were ruled from Prague at one time. Most Czech historical texts use the term in this manner when discussing the Middle Ages. Other sources use the term to refer only to the core Czech areas of Bohemia, Moravia and the former Austrian Silesia. For many topics, a distinction between the two definitions is not necessary, as the Czech lands have been more-or-less co-extensive with the modern-day Czech Republic since the eighteenth century.