Prior to transitioning, Petrillo won 11 national titles in the men's category.
Valentina Petrillo is set to become the first openly transgender athlete to participate in the Paralympic Games after the visually impaired sprinter was selected to represent Italy in the women's 200 and 400 metres races in Paris.
The 50-year-old, who transitioned in 2019, won bronze medals in both events at the World Para Athletics Championships last year in Paris.
Prior to transitioning, Petrillo won 11 national titles in the men's category.
"I still find it hard to believe it and I'm keeping my feet on the ground because my chance to participate in Tokyo was missed by a whisker," Petrillo said in a statement on Monday.
"I will only start thinking about the Paris Games once I arrive in France."
Diagnosed with Stargardt's syndrome at the age of 14, Petrillo's visual abilities are limited to 1/50th of the normal range.
International Paralympic Committee (IPC) President Andrew Parsons told BBC Sport that while Petrillo is welcome in Paris under World Para Athletics policies, he wants to see the sporting world "unite" on its transgender policies.
The governing bodies of many sports including athletics, cycling and swimming have tightened their participation rules for transgender athletes in elite women's competitions over the last couple of years.
However, the IPC allows governing bodies to set their own policies and World Para Athletics permits an individual legally recognised as a woman to compete in the category for which their impairment qualifies them.
Critics of transgender inclusion in women's sport say going through male puberty imbues athletes with a huge musculo-skeletal advantage that transition does not mitigate.
LGBT advocacy groups say excluding trans athletes amounts to discrimination and that not enough research has been done into the impact of transition on athletic performance.
The 2024 Paris Paralympics run from August 28 to September 8.
