The Reichsadler ("Imperial Eagle") was the heraldic eagle, derived from the Roman eagle standard, used by the Holy Roman Emperors and in modern coats of arms of Germany, including those of the German Empire, the Weimar Republic and Nazi Germany. The same design has remained in use by the Federal Republic of Germany since 1945, but under a different name, now called Bundesadler "Federal Eagle" rather than "Imperial Eagle".

The Reichsadler can be traced back to the banner of the Holy Roman Empire, when the eagle was the insignia of the Imperial power as distinguished from the Imperial states. It was meant to embody the reference to the Roman tradition (translatio imperii), similar to the double-headed eagle used by the Palaiologi emperors of the Byzantine Empire or the tsars of Russia.

The eagle began to appear in the 9th century on the banner of Charlemagne and his successors. A double-headed eagle was attributed to Frederick II of Hohenstaufen in the Chronica Majora by Matthew Paris about 1250, it also appeared on the seal of the Imperial city of Kaiserswerth in the 13th century. The Reichsadler was widely used by Imperial cities such as Lübeck, Besançon or Cheb to underline their immediacy. The Teutonic Order under Hermann von Salza had the privilege to display the Imperial eagle in their coat of arms, granted by Emperor Frederick II. The black eagle was later adopted when the Teutonic State was transformed into the Duchy of Prussia in 1525.