Deportivo La Coruna have appointed Domingos as their new coach following the dismissal of Jose Luis Oltra on Sunday night.
Oltra and assistant Chema Sanz leave the club at the foot of La Liga table with just two wins from 17 matches this season. He led Depor back into the top flight at the first attempt last season.
Club president Augusto Cesar Lendoiro announced the news at a press conference held at the club's stadium.
According to Deportivo's official website, Lendoiro said: "We felt that now was the right time for a change. In the next few hours, or even tomorrow, we hope to introduce the new coach.''
Depor began this season promisingly with an opening win followed by three draws. However a severe decline in their fortunes followed, and Deportivo went to the winter break on the back of a 2-0 defeat against fellow strugglers Espanyol, leaving them fighting for their lives in the top flight.
They have mustered 12 points so far, leaving them three points adrift of the last team in a safe position, 17th-placed Celta Vigo.
Within hours the club's official Twitter account revealed that former Braga and Sporting Lisbon coach Domingos will take charge of the team until the end of the season.
Depor also announced that Oltra will attend training on Monday morning to say a final farewell to the players before then addressing the media.
Information from the Press Association was used in this report