Walter Veltroni, an Italian writer, journalist and politician who served as mayor of Rome from 2001 to 2008, will conduct the ceremony, a representative for the Venice Municipality confirmed, reported People magazine.
Veltroni is a close friend of Clooney's, and the Oscar-winning actor has likened him in the past to President Barack Obama, saying that the former mayor appealed 'to the young, he speaks of hope and a clean environment, (which is) rare in Italian politics'.
Clooney, 53 is set to marry Alamuddin, 36, in Venice, Italy later this month.