The Hollywood star had been considering holding the ceremony at Highclere Castle, the home of Downton Abbey, as well as his luxury villa on the shores of Lake Como, but is said to have set his sights on Venice.
George, 53, and the beautiful human rights barrister, 36, were spotted having dinner together in the romantic city – famous for its canals and idyllic gondola rides – last month.
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It is believed the handsome couple may well have been scouting possible locations for their September wedding.
George has got to know Venice well through the famous Film Festival held there every year – he most recently attended to showcase Gravity, in which he co-starred alongside Sandra Bullock, and was seen at the wheel of a luxury speed boat.
George Clooney pictured on the red carpet at Venice Film Festival last year
It was widely speculated that the duo would opt to say "I do" in George's villa, which is also one of his favourite holiday spots, but according to sources, Amal felt that it was too public.
"George and Amal want to be married in Italy, but they need a location that offers them and their guests privacy," a source told the New York Post's Page Six.
George Clooney at the wheel of a speed boat in Venice
George and London-based Amal, who is of Lebanese origin, got engaged at the end of April after having dated for seven months.
Guests invited to their big day include Brad Pitt, Angelina Jolie, Sandra Bullock, and Matt Damon.
Should the wedding take place in September as planned, it would be around the time of their one-year anniversary.