"Our head coach, Ismail Kartal, has informed our management of his decision to resign, and following discussions, this decision has been evaluated with mutual understanding and respect," the club said in a statement shared on social media.
"We thank Ismail Kartal for his efforts, dedication, and commitment to Fenerbahce. We wish him success in his future career."
Kartal, 65, was appointed Fenerbahce manager for the fourth time in June 2026. The Istanbul giants dismissed Domenico Tedesco after the 2025/26 campaign, which ended in heartbreak for Fenerbahce as bitter rivals Galatasaray won the Super Lig title by three points.
On Monday, Fenerbahce lost 2-1 to Galatasaray in the Intercontinental Derby. It was the club's third league defeat of the season, and Fenerbahce are currently sixth in the Super Lig, six points behind Galatasaray.
The club are bidding to win their first league title in 13 years after spending over €100 million on summer transfers, including Mason Greenwood, Romelu Lukaku, Vedat Muriqi, and Nathan Ake.
The Kadikoy residents are also on just two points in the UEFA Champions League after three rounds, having drawn with Roma (1-1) and Slavia Prague (2-2), while losing 6-0 to Aston Villa.
Kartal had already tried to resign once this season, announcing his exit in the post-match press conference after the Champions League draw against Roma.
He said: "I stepped down from my duties this evening. I made this decision to clear the way for my club. I resigned while the path is still clear, with no intention of ever returning."
The club rejected Kartal's resignation the following day, with club president Aziz Yildirim meeting with Kartal and convincing him to stay in an "emotional meeting" after he had already packed his office.
With Kartal officially gone, assistant manager Dirk Kuyt is set to lead the team in this weekend's Super Lig match against Goztepe.