The report cites Elisa Di Lupo, a spokesperson at the Florence mayor's office. The couple rented the fort for approximately $410,000 and a Protestant minister is set to preside over the ceremony.
The rapper and Kardashian were engaged in October 2013.
Kanye West's proposal to Kim Kardashian aired on E! as part of the network's Keeping Up With The Kardashians reality television series.
"I can't believe I'm engaged," Kardashian said on the show. Kardashian's mother, Kris Jenner, also spoke about the engagement event. "It's an experience I will never forget," Jenner said on the show.
"Kim, I couldn't be happier for you and Kanye, I'm so obsessed with you," Kim's sister Khloe Kardashian said in a speech to the couple. "I love you and I can't wait to have you legally as a brother, but I still consider you as a brother now. I just cannot wait for this wedding. I'm so excited. And let's have more kids, more babies."