He was bought by Spanish club Sevilla FC in late January 2007[5] and spent the vast majority of the remaining season with the reserves, which he helped to achieve promotion to Segunda División.

He made his first-team debut on 9 May 2007, as a substitute for Julien Escudé in a 2–0 home win against Deportivo de La Coruña in the semi-finals of the Copa del Rey.

[6][7] Fazio started 2007–08 registered with both teams; however, due to the absences of Javi Navarro (knee, entire campaign missed) and Escudé (pubis, less than half of possible games), he ended up playing an important part on a side that finished fifth in La Liga.

[18] Still bothered with some physical problems in 2010–11,[17] Fazio played the most he had in years, appearing in 19 matches – 17 starts – as Sevilla ranked fifth and qualified for the Europa League.

[19] On 18 October he started on his Premier League debut at Manchester City, but was given a straight red card for denying Sergio Agüero a goalscoring opportunity in the penalty area, in an eventual 4–1 defeat.

[21] On 31 January 2016, after only one competitive game in the first part of the season (a 1–2 home loss to Arsenal in the League Cup)[22][23] Fazio returned to Sevilla on a five-month loan.

[30] After the arrival of new manager José Mourinho, he did not receive any playing time and was ultimately made to train on his own; as a result, he took legal action against the club.