Adolf of Nassau (1817-1905) was the last Duke of Nassau, and the fourth Grand Duke of Luxembourg. Adolph became Duke of Nassau in 1839, after the death of his father, William. He supported Austria in the Austro-Prussian War of 1866. After Austria's defeat, Nassau was annexed to Prussia. In 1890, when Queen Wilhelmina of the Netherlands was excluded from the succession to Luxembourg by the Salic Law, the Grand Duchy passed to the dispossessed Duke Adolph. Luxembourg, even with Grand Duchesses, has been in the line of Adolph ever since.

He was succeeded by his son, William IV