Marco Ghiani grew up in Sardinia and did not come from a racing background, but he was encouraged to chase his ambition of becoming a jockey by fellow Italian rider Dario Vargiu. He later moved to Newmarket, where he attended a course at the British Racing School. 

Ghiani started out riding for Luca Cumani in 2017 but joined the stable of Stuart Williams as an apprentice when Cumani retired, making a bright start to 2018, achieving one second and three third place finishes in his first 11 rides. His breakthrough came in 2019 when he won 22 races, followed by 19 races in 2020.  

In 2021, he became Champion Apprentice, topping 100 winners for the year, and riding out his claim in the process. Ghiani formed a strong partnership with the Saeed Bin Suroor trained Real World, on whom he got his first Royal Ascot win in the Royal Hunt Cup, before following up in the Steventon Stakes and Strensall Stakes. Ghiani was appointed as the retained rider for leisure tycoon Peter Harris for the 2023 season, providing him with success in France. 

Later in 2023, Ghiani followed his victory in France with a win in the St. Leger Italiano in Italy. Further success in Italy came in 2025 when winning the Derby Italiano aboard the Marco Botti trained Molveno.