Admiral Juan Bautista Aznar Cabañas, KOGF (Cádiz, 1860–Madrid, 1933) was the Prime Minister of Spain from the resignation of Dámaso Berenguer y Fusté on to the deposition of King Alfonso XIII and the proclamation of the Spanish Second Republic on April 14, 1931. An admiral of the Spanish Navy, he was made Prime Minister at a time of intense crisis, in the first months of 1931, when the monarchy was on the verge of falling under popular pressure for a republic. His attempts to save the crown failed, and King Alfonso had to go to exile.