Alecu Ioan Sion (September 28, 1890 – November 24, 1942) was a Romanian soldier and a major general in the Land Forces. Born in Pitești, he attended the military high school from Iași and then studied at the military school for artillery and engineers officers in Bucharest from 1909 to 1911. He entered the army as a second lieutenant in 1911. Promoted to lieutenant in 1914, he later took part in World War I, commanding a unit within the 2nd Artillery Regiment. During the Romanian Campaign of 1916, he stood out at the battles of Perșani and Porumbacu, for which he was awarded the Order of the Crown of Romania, Knight class. He was promoted to captain in 1917, and fought in the battles in Moldavia during that summer.