Marcel Martin Koller (born 11 November 1960) is a Swiss professional football manager and former player who is the current head coach of Al Ahly in the Egyptian Premier League.

Koller's career as coach started at the Swiss club FC Wil in the 1997–98 season.

Highlights were two memorable home victories against arch rivals Borussia Dortmund (2–0) and FC Schalke 04.

The VfL Bochum lost three important players in the summer break 2007 so that most observers were rather skeptical about the club in the coming season.

Especially the release of crowd pleaser Tomasz Zdebel in the winter break caused many frictions with the fans.

With only four points out of the first six matches VfL Bochum started again rather disappointing and the public pressure grew continuously.

After a 2–3 home defeat by FSV Mainz more than two thousand supporters gathered at the stadium to demand his dismissal.

[9] On 9 September 2022, Koller signed a two-year contract with Egyptian club Al Ahly.

[10] On 28 October 2022, he won his first title with Al Ahly after beating Zamalek SC 2–0 in the 2021–22 Egyptian Super Cup at Hazza bin Zayed Stadium in Abu Dhabi, United Arab Emirates.

[11] On 10 April 2023, he won his second title after beating Pyramids FC 2–1 in the 2021–22 Egypt Cup final.

Following this victory, he secured the African Champions League on June 11, with a 3–2 aggregate win against Wydad AC.

[13] A month later, on July 15, his club triumphed in the 2022–23 Egyptian Premier League, finishing the season with only one defeat.

He then led the team to win the 2023–24 CAF Champions League against Espérance de Tunis, extending their record in the competition to 12 titles.