During the 2017–18 Grand Prix series, Fernández first competed in the 2017 Cup of China. He placed 3rd in the short program after popping his planned quadruple-triple combination, scoring 90.57 points. He made several mistakes in the free skate to finish 6th in this segment (162.49) and 6th overall (253.06). It was revealed after the competition that Fernández had been suffering from stomach problems. His second Grand Prix assignment was the 2017 Internationaux de France in Grenoble. Fernández won the short program with a clean skate for which he received 107.86 points, the 5th highest short program score on record at the time of the event. In the free skate, Fernández fell twice and stepped out of the landings of three other jumps to finish 2nd behind Shoma Uno in the segment with 175.85 points. His lead from the short program was enough to win the event overall with 283.71 points. This was the 7th career Grand Prix title for Fernández.