Joaquín Pérez Rufete, the team’s sporting director, will replace Fernández through the end of the season.
Espanyol said the decision was based on “the team’s performances” and “in hopes of keeping the club in the first division.”
Espanyol is eight points from safety with seven rounds left. It resumed the season with a win against Alavés, then drew with Getafe and lost to Levante and Real Betis.
Fernández, who had been with Espanyol since December 2019, released a statement saying he was “eternally grateful” for his time with the Barcelona club.
Fernández’s assistants also were relieved of their duties.
Fernández was the second coach fired since the Spanish league resumed, following Rubi’s dismissal from Real Betis last weekend.