Maximilian I (Spanish: Fernando Maximiliano José María de Habsburgo-Lorena; German: Ferdinand Maximilian Josef Maria von Habsburg-Lothringen; 6 July 1832 – 19 June 1867) was an Austrian archduke who became emperor of the Second Mexican Empire from 10 April 1864 until his execution by the Mexican Republic on 19 June 1867.
A member of the House of Habsburg-Lorraine, Maximilian was the younger brother of Emperor Franz Joseph I of Austria. Before becoming Emperor of Mexico, he was commander-in-chief of the small Imperial Austrian Navy and briefly the Austrian viceroy of Lombardy–Venetia, but was removed by the emperor.