Don Álvaro de Bazán, 1st Marquis of Santa Cruz, lord of the Villas of Viso and Valdepeñas, largest Commander of León, Member of his Majesty Council, Captain General of the Navy, of the Ocean Sea and the people's war of Kingdom of Portugal (Spanish: Don Álvaro de Bazán, marqués de Santa Cruz de Mudela) (Granada, December 12, 1526 – Lisbon, February 9, 1588), is a Spanish admiral born at Granada.

His grandfather, Álvaro de Bazán, had taken part in the conquest of Granada in 1492, and his father, with the same Christian name and well-known as "D. Álvaro the elder", who had taken part together with Giovanni Andrea Doria and others marines in the recapture of Tunis in 1535, was distinguished in the service of Charles V, by whom he was made general of the galleys or commander-in-chief of the Spanish naval forces in the Mediterranean.

The future admiral follows his father in his youth, and is employed in the high command of the Spanish navy at a fairly early age.

He is a member of the Military Order of Santiago (St. James).

In 1564, he aids in the capture of Peñón de Vélez de la Gomera, and commands the division of galleys employed to blockade Tetuan, and to suppress the piracy carried on from that port.

The service is said to have been successfully performed.

Bazán certainly earns the confidence of Philip II, by whom he is appointed to command the galleys of Naples in 1568.

This post brings him into close relations with John of Austria, when the Holy League is formed against the Turks in 1570.