Mecklenburg-Strelitz is a duchy in northern Germany, consisting of the eastern fifth of the historic Mecklenburg region, roughly corresponding with the present-day Mecklenburg-Strelitz district (the former Lordship of Stargard), and the western exclave of the former bishopric of Ratzeburg in modern Schleswig-Holstein.

At the time of its establishment, the duchy borders on the territory of Swedish Pomerania in the north and of Brandenburg in the south.