Marmoush started his career with Wadi Degla SC in Egypt. In August 2017, he joined Wolfsburg‘s reserve side in Germany. He made his professional European debut with the club, VfL Wolfsburg, in 2020. In July 2023, he moved to Eintracht Frankfurt on a free transfer with a contract lasting until 2027. His market value was $43.4 million as of October 2024, according to Transfermarkt. Marmoush scored nine goals in seven matches in the 2024-2025 season, becoming the Bundesliga's top scorer, as of October 23, 2024.