Ona Carbonell Ballestero (born 5 June 1990) is a Spanish synchronized swimmer.

[1] She competed in the women's duet at the 2016 Summer Olympics, with Gemma Mengual, finishing in fourth place.

[1] During her preparation for the 2020 Summer Olympics, Carbonell gave birth in August 2020.

Despite medical advice not to train for six months, Carbonell returned in four weeks and competed at the Olympics, where she came seventh in the team event.

[2][3] A documentary, Starting Over, was made of her grappling with the roles of mother and athlete.