Sanchez del Amo, 39, steps into the hot seat for the first time as a senior coach, a day after Fernandez was relieved of his duties following Deportivo's 1-1 draw with Cordoba on Wednesday.
Deportivo are fourth-from-bottom in the La Liga standings, two points above the relegation zone with eight matches remaining and Sanchez del Amo will be tasked with preserving the club's top-flight status, starting against Real Sociedad on Saturday.
"I would like to thank the president for making it possible that this city, and this club – both important parts of my career as a player, can now be a vital part of my career as a coach," Sanchez del Amo said.
"I will be making my managerial debut with Depor in the Primera Division. It's a dream come true."
Deportivo president Tino Fernandez added: "Victor was part of the legendary Depor side and for all that he achieved as a player, he really needs no introduction.
"I would like to thank Victor for showing faith in this project; I encourage him to succeed and wish the very best of luck in this new venture."
