Prince Andrew celebrated his 60th birthday on February 19 and Eugenie's followers were quick to wish him a happy birthday.
"No matter what is going on he is still your Dad. Happy Birthday Prince Andrew xx" one commented.
"Happy birthday to His Royal Highness. Sending Love, support and good energies to Your Royal Highness and all members of The Royal Family 😚" wrote another fan.
Another commented: "Happy birthday for HRH The Duke of York! Send all love and suport for you and your family. Admire all hard work of all of you! 🎉👏🏻"
Queen Elizabeth also publicly wished her son a happy birthday with a post shared to The Royal Family Instagram account.
Two photos were published; one of Andrew as a baby and a second more recent photo.
The caption read: "On this day in 1960, Prince Andrew was born at Buckingham Palace, the first child born to a reigning monarch for 103 years. Happy Birthday to The Duke of York."
Andrew's ex-wife, Sarah Ferguson also posted a sweet birthday message on her Instagram.
"Happy 60th birthday to Andrew," she wrote, alongside a black-and-white photo of the royal at home.
Eugenie's latest post comes after she has seemingly dropped a subtle clue that suggests she might be a bridesmaid at Princess Beatrice’s upcoming wedding to fiancé Edoardo Mapelli Mozzi.
Taking to Instagram, the 29-year-old shared a sweet throwback snap of the herself and Bea as youngsters when they were bridesmaids for their nanny Alison Wardley.
“She's so excited.... Today the family announced Beatrice will marry Edo on 29th May 2020. Very proud of this moment,” Eugenie captioned the retro snap.
Enthusiastic fans were quick to take to Instagram to comment on the delightful pic, with one person writing: “Very happy for Princess Beatrice and your family!”
Another person stated: “You must be a very proud sis! Wish the couple all happiness and may the wedding preparation go smoothly.”
A third person added: “Awww congrats to you and your sister!!”
While the post may just seem like a sweet sisterly gesture, it could be that Eugenie was giving fans a subtle hint she is going to carry out the bridesmaid role again at Bea’s wedding.
Eugenie is yet to reveal her role in the wedding, but if history is anything to go by, the snap could be a sign she is set to lead her sister down the aisle in May.