The 30-year-old has signed a contract that will keep him at the club until the end of the season and joins the club for an undisclosed fee.
Cesar joined Hertha from Al Ahli only a year ago, but failed to make an impact at the Bundesliga side.
“I’m happy to return to Al Ahli once again. I feel that I have returned home, especially with the way my old friends received me when I arrived at the club,” said Cesar on the club’s official website.
“I have a lot of memories with Al Ahli and I achieved several titles, and hopefully my return will help the team.”
