Alexandru C. Plagino, or Plajino (August 21, 1821 – October 4, 1894), was a Wallachian-born Romanian politician.
Born to a boyar family of Greek origin, his parents were the great postelnic Constantin Plagino and his wife Eufrosina, the daughter of Alexander Mourousis.
After the Union of the Principalities, he was Finance Minister in the Wallachian government from July 1861 to January 1862, under Dimitrie Ghica.
During the Romanian War of Independence, he served as high commissioner to the general staff of the Imperial Russian Army, from April to July 1877.
He was sent to Madrid and Lisbon in order to notify the royal courts there of Romania's independence, spending the year 1879 and early 1880 on the Iberian Peninsula.