The former couple divorced 15 years ago. They are the parents of Princess Beatrice, 22, and Princess Eugenie, 21.
"He's a great man and a first-rate father and the bestest friend," Ferguson told Harper's Bazaar about Prince Andrew in an interview for the maagzine's June issue. "I love him. He's my soulmate. It's actually what we said in front of God at the altar: We honor and respect each other until death do us part. The only thing is, he has girlfriends and I have boyfriends."
Ferguson made headlines last year when she attempted to sell access to her former husband to a journalist.
The scandal kept her off the guest list of her nephew Prince William's wedding at London's Westminster Abbey last month.
Ferguson and Prince Andrew married in the same location in 1986.