The McFly singer joked with his bride-to-be on Twitter ahead of the wedding earlier today.
Fletcher tweeted: "I'm sure I'm meant to be doing something today."
Falcone later replied: "naaah! Just your average boring Saturday! Xxxx (sic).
The couple will be joined by friends and family at the ceremony in London's Marylebone. Fletcher's bandmates Danny Jones, Harry Judd and Dougie Poynter will act as joint best men.
Just before leaving for the wedding, Fletcher tweeted to his fans: "Ok, this is probably my last tweet for today. The next time I tweet I will be a married man!...unless @giovannafalcone stands me up....."
Last night, Falcone wrote: "Okay... My dress is hung up nicely, as are the bridesmaid dresses... Everything else is laid out in preparation. I think I'm ready!!!"
Harry Judd also tweeted earlier today: "It's a beautiful day for a wedding :-)"
The pair became engaged last year after Fletcher proposed in April 2011.
McFly have been working with One Direction for the 'What Makes You Beautiful' group's second LP.