Gasparo Contarini (16 October 1483 – 24 August 1542) was an Italian diplomat, cardinal and Bishop of Belluno. He was one of the first proponents of the dialogue with Protestants, after the Reformation.
He was born in Venice, the eldest son of Alvise Contarini, of the ancient noble House of Contarini, and his wife Polissena Malpiero. After a thorough scientific and philosophical training at the University of Padua, he began his career in the service of his native city. From September 1520 to August 25 he was the Republic's ambassador to Charles V, with whom Venice was soon at war, instructed to defend the Republic's alliance with Francis I of France. Though he participated at the Diet of Worms, April 1521, he never saw or spoke with Martin Luther. He accompanied Charles in the Netherlands and Spain.
He participated at the Congress of Ferrara in 1526 as the Republic's representative; at the Congress the League of Cognac was formed against the Emperor, allying France with Venice and several states of Italy. Later, after the Sack of Rome (1527), he assisted in reconciling the emperor with Clement VII, whose release he had obtained, and with the Republic of Bologna. Upon his return to Venice, he was made a senator and a member of the Great Council.
In 1535, Paul III unexpectedly made the secular diplomat a cardinal in order to bind an able man of evangelical disposition to the Roman interests. Contarini accepted, but in his new position did not exhibit his former independence. At the time he was promoted to cardinal, May 21, 1535, he was still a layman. However, already in October 1536 he was appointed Bishop of Belluno One of the fruits of his diplomatic activity is his De magistratibus et republica Venetorum.