The Second Mexican Empire, officially the Mexican Empire, was a constitutional monarchy established in Mexico by Mexican monarchists in conjunction with the Second French Empire. The period is sometimes referred to as the Second French intervention in Mexico. French Emperor Napoleon III, with the support of the Mexican conservatives, clergy, and nobility, established a monarchist ally in the Americas intended as a restraint upon the growing power of the United States. It has been viewed as both an independent Mexican monarchy and as a client state of France. Invited to become emperor of Mexico by Mexican monarchists who had lost a bloody civil war against Mexican liberals was Austrian Archduke Maximilian, of the House of Habsburg-Lorraine, who had ancestral links to rulers of colonial Mexico. His ascension to the throne was then ratified through a fraudulent referendum. Maximilian's wife and empress consort of Mexico was the Belgian princess Charlotte of the House of Saxe-Coburg and Gotha, known in Mexico as "Carlota".

The Second French Empire was an Imperial Bonapartist regime of Napoleon III from 14 January 1852 to 27 October 1870, between the Second and the Third French Republics. The period was one of significant achievements in infrastructure and economy, while France reasserted itself as the dominant power in Europe.