Spurs have confirmed that the loan deal includes an obligation to buy the player at the end of the season.
The 27-year-old follows City teammate Savinho to the Tottenham Hotspur Stadium, with the Brazilian also signing for the club over the past few days/yesterday/last week.
Marmoush is the latest name in a busy summer for Spurs, who have also added Savinho, as well as Andy Robertson, Marcos Senesi, Jan Paul van Hecke, Martin Dubravka, Mateus Fernandes and Sandro Tonali.
"It feels amazing to be here. I'm so excited to get started with the team and I can't wait to meet the fans," he said.
"Tottenham Hotspur is one of the biggest clubs in England, if not the world, and the project was very attractive to me.
"I've spoken with the Head Coach, I loved what he had to say and I'm sure our passion for the game will go very well together."
The Epygtian arrives in London after 18 months in Manchester, where he featured 62 times, netting 16 goals and providing six assists.