The 28-year-old – the only surviving heir of Greek shipping magnate Aristotle Onassis and the only child of his daughter Christina – was bridesmaid for her half-sister Sandrine at a church ceremony in the tiny village of Villeny, Northern France.
The rainy weather did nothing to dampen the mood as the bridal party exited the church. Athina, who sheltered under an umbrella, carried a bunch of pink roses and gathered her dress up, revealing pink ballet pumps.
She was accompanied to the wedding by her husband of eight years, Brazillian equestrian Álvaro de Miranda Neto (not pictured).
The couple prefer to stay out of the spotlight, living a low key life in Sao Paulo. They made an exception, however to attend the nuptials of Sandrine, daughter of Athina's father Thierry Roussel and his second wife, Marianne Landhage.
Twenty-six-year-old Sandrine looked beautiful in a long-sleeved white gown with sweetheart neckline as she said "I do" at the same church where her parents wed.
After the service the newlyweds were driven away in a Rolls Royce decked out in pink and white ribbons.