It was in his hometown of Los Palacios y Villafranca, in the Andalusian province, that a young Fabián first discovered football. His passion for the game led him to the Real Betis youth academy at just 8 years old, where he developed his skills as a midfielder across all youth levels.
In 2014, having just come of age, he joined the Betis reserve team, with whom he was crowned Spanish second division champion. He made his first-team debut the following summer before going on loan to Elche CF in the winter to continue his development. That was enough to catch the eye of Napoli, who signed the 1.89m playmaker to bring his talents to Serie A.
Under Carlo Ancelotti and later Gennaro Gattuso, Fabián Ruiz established himself as a regular starter, earning a call-up to the Spanish national team (15 caps). He even won the 2023 UEFA Nations League with La Roja, starting in the final.