Hesse-Darmstadt or the German Hessen-Darmstadt is a name that describes:
- Landgraviate of Hesse-Darmstadt (Landgrafschaft Hessen-Darmstadt) (1567-1806), a state of the Holy Roman Empire
- Grand Duchy of Hesse (Großherzogtum Hessen) (1806-1918), formed after the dissolution of the Holy Roman Empire, and later member of the German Confederation and the German Empire
- People's State of Hesse (Volksstaat Hessen) (1918-1945), created after the abolition of the German monarchies following the revolutions of 1918-1919, a state of Germany during the time of the Weimar Republic