Adolphe Niel (4 October 1802 – 13 August 1869) was a French Army general and statesman, also Marshal of France. He was born at Muret, Haute-Garonne and entered the École Polytechnique in 1821. Niel entered the engineer school at Metz, became lieutenant in the Engineers Corps in 1827, and captain in 1833. At the storming of Constantine, Algeria, Niel led the engineer detachment with one of the storming parties, and his conduct gained for him the rank of chef de bataillon in 1837. Niel was promoted to lieutenant colonel in 1840 and to colonel in 1846. His next war service was as Chief of Staff to General Vaillant during the 1849 siege of Rome, after which he was made general of brigade and director of engineer services at headquarters.