德意志帝國（德文：Deutsches Reich；英文：German Reich）是德國1871-1945年的正式國號。
不過，一般中文語境裏所說的“德意志帝國”指的是普魯士霍亨索倫王朝統治下的德意志帝國，也稱德意志第二帝國。
Deutsches Reich was the official name for Germany from 1871 to 1945 in the German language. The direct literal translation, "German Empire", is used only when describing Germany under Hohenzollern rule (until 1918). For the entire 1871–1945 period, the English name given for Germany was the partially translated "German Reich" (pronounced /ˈdʒɜrmən ˈraɪx/). Following the German Kaiser's (Emperor's) abdication of the German Empire after World War I, the word "Empire" was dropped and the official name used in English was the "German Reich". Informally, this nation was also simply known as Germany.
The name "Deutsches Reich" was also often applied in contemporary maps to the supranational Holy Roman Empire (911–1806). The history of Germany during the time of the (second) German Reich is conventionally broken into three distinct periods:
* the monarchy under Hohenzollern rule, known in English as the German Empire (1871–1918)
* the democratic republic, known retrospectively as the Weimar Republic (1919–33)
* the totalitarian dictatorship commonly known as the Third Reich or Nazi Germany (1933–45)
Following the de-facto annexation of Austria in 1938, Germany informally named itself the Greater German Reich (German: Großdeutsches Reich). This name was made the official state name only during the last two years (1943–45) of Nazi rule.