Aston Villa have appointed Roberto Olabe as their new president of football operations after Monchi stepped down from his role.
Olabe moves to Villa Park with immediate effect and arrives after leaving his role as director of football at Real Sociedad.
Monchi, who was at Villa for just over two years, will take on an advisory role with V Sports, the company that owns Aston Villa.
Olabe previously worked with Villa head coach Unai Emery at Almeria in Spain, while he has also worked in Qatar and Ecuador.
Monchi said: "I would like to thank everyone connected with Aston Villa for the support and warmth they have shown me since I joined the club, especially Unai and Damian [Vidagany, director of football operations], who I have worked especially closely with over these last two years.
"I must also thank our owners, Nassef Sawiris, Wes Edens and Michael Angelakis for their confidence and their support. I would also like to say a special thank you to all the staff at Aston Villa as well as the players.
"Lastly, a big thank you to the supporters. We have enjoyed so many special moments together and I look forward to continuing to support V Sports in an advisory role."
Monchi's work helped steer Villa into last season's Champions League, although they narrowly missed out on returning this campaign having finished sixth in the Premier League.
Among the players signed under his guidance were Morgan Rogers, Youri Tielemans and Amadou Onana.
Monchi also secured the loan signings of Marcus Rashford and Marco Asensio last season, while he brought Harvey Elliott and Jadon Sancho in on Deadline Day earlier this month.
It is unclear why Monchi stood down. Villa are currently in the Premier League's bottom three and yet to win after five games.
Olabe was long linked with the job at Arsenal after Edu Gaspar left, but they ultimately hired Andrea Berta from Atletico Madrid.
Emery: Lazy Villa need to rediscover identity
The news of Monchi's departure comes after Emery described his Aston Villa team as "lazy" and called on them to "recover their identity" after their winless start to the season continued at Sunderland.
Matty Cash's thunderous strike ended a run of 427 minutes without a Premier League goal at the Stadium of Light, but Wilson Isidor struck a late equaliser to earn the Black Cats a point in a 1-1 draw on Wearside.
Emery's side have not won a Premier League game since they beat Tottenham 2-0 at Villa Park on May 16 and sit in 18th place in the table after five games.
"We are not playing like I want," the Spaniard said in his post-match press conference.
"Of course we have to adapt some players in our structure and we will need time with them, but other players, they know how we want to try to control the game with the ball; it's with the ball, more than without the ball.
"We were conceding a lot of chances, chances starting with their goalkeeper. Long balls, second actions, corners in our box. And of course, like that, we are conceding chances.
"I told them the same thing I am telling you. We have to recover our identity. Of course, we have to try to recover our personality, confidence and personality to play.
"I am frustrated for how we played, how we are not feeling comfortable with our style."
Richards: No urgency from Villa - they are miles off it
Sky Sports' Micah Richards on Super Sunday:
"Villa need more. The urgency wasn't there [against Sunderland]. Everything was too slow. I thought they'd pick up the tempo in the second half and it just wasn't there. They didn't create enough.
"Something's not right at this moment in time. I believe the manager will get it right, but at this moment, they are miles off it."