Sheppard, who is 37 years Ferry's junior, donned a white Lanvin dress for the beachfront ceremony, held Jan. 4 at the Amanyara resort on the Turks and Caicos Islands.
The singer has long had a penchant for dating younger women.
After splitting from first wife Lucy Helmore, Ferry -- who also romanced Jerry Hall -- dated dancer Katie Turner, who was 35 years his junior. He reportedly began dating Sheppard in 2009, after she ended a relationship with one of his four sons with Helmore.
"The interesting thing is -- and I don't want to say the wrong thing in case I get into trouble with my girlfriend -- you never really meet people your own age who aren't married," Ferry told the Mail On Sunday's Live magazine last year.
"I'm very fortunate that I work in music, where you're in touch with different age groups, either the audience or people you work with. It does help," he continued. "Obviously I'm not ageist!"