Sarah Ferguson paid tribute to her "best looking" ex-husband Prince Andrew on his birthday.

Prince Andrew (c) Sarah Ferguson Instagram

Prince Andrew (c) Sarah Ferguson Instagram

The 58-year-old author divorced the royal - with whom she has daughters Princess Beatrice, 29, and Princess Eugenie, 27 - in 1996, but showed she still cares for her former spouse by sending him her best wishes on his 58th birthday on Monday (19.02.18).

Alongside an old black and white photograph of a young Andrew, she captioned the post: "Happy birthday to the best man, father, friend....Prince Andrew. Feb 19...ooh the best looking @hrhthedukeofyork #birthday (sic)"

The Duke of York and Sarah tied the knot on July 23, 1986, at Westminster Abbey in London, but after 10 years of marriage they parted ways.

Sarah's heartfelt message to Andrew comes after she previously admitted she doesn't regret her past, and wouldn't do anything differently given the chance.

She said: "If I could turn back time, I still wouldn't change anything."

Though the pair are no longer married, Sarah insists they are still very "good friends".

She added: "We're good friends and communicate very well - a prerequisite for the children to feel good."

The TV personality admitted her two daughters are "evidence of good parenting", and that she is extremely "proud" of the women they've become.

She said: "I am very proud of my beautiful girls and we have a good relationship. They're evidence of good parenting, I'd say. Being a good mother is listening to your own heart, standing firm in what you believe in and providing security."

Andrew and Sarah will come together for the wedding of their daughter Eugenie and her fiancé Jack Brooksbank at St. George's Chapel at Windsor Castle this autumn.

It has also been reported that Sarah will be attending Prince Harry and Meghan Markle's wedding at the same venue on May 19.