Benitez, who won the Champions League with Liverpool in 2005, the UEFA Cup with Valencia (2004) and the Europa League with Chelsea (2013), returns to coaching over a year after being sacked by Everton in January 2022.
He will take charge of LaLiga side Celta on their 100-year anniversary, succeeding Carlos Carvalhal, who took was sacked earlier this month after a difficult season in which they had to fight until the last game to avoid relegation.
Benitez's last experience in Spain was in the 2015-16 season with Real Madrid, when he replaced Carlo Ancelotti only to be sacked six months later after a series of bad results, being replaced by Zinedine Zidane in January 2016.
"Rafa Benitez is one of the most successful coaches in the history of our country and has coached world-class teams in the main European leagues," Celta said.
"(In) our Centenary season, an unforgettable ... event for Celta's fans, (we will have) a formidable leader on the bench."
