Carlos Romero Giménez, sometimes misspelled Jiménez, was a Spanish soldier loyal to the Spanish Republic, and one of the most prominent figures in the Siege of Madrid during the Spanish Civil War. Subsequently, a member of the French Resistance, he fought the Nazi occupation from Bordeaux as part of the Maquis. He was President of the Spanish League for Human Rights.

The siege of Madrid was a two-and-a-half-year siege of the Republican-controlled Spanish capital city of Madrid by the Nationalist armies, under General Francisco Franco, during the Spanish Civil War (1936–1939). The city, besieged from October 1936, fell to the Nationalist armies on 28 March 1939. The Battle of Madrid in November 1936 saw the most intense fighting in and around the city when the Nationalists made their most determined attempt to take the Republican capital.