Rafael Nadal won the Monte Carlo Masters 11 times. His victories came at the clay-court tournament in Monaco between 2005 and 2018, making him its most successful singles champion.
Nadal won eight consecutive Monte Carlo titles from 2005 through 2012. He returned to the winner’s circle in 2016, 2017, and 2018, bringing his total to 11. His dominance was especially striking because Monte Carlo is one of the premier clay-court events on the ATP Tour and attracts the world’s best players.
The tournament is officially the Monte-Carlo Masters and is held at the Monte Carlo Country Club in Roquebrune-Cap-Martin, France, just outside Monaco. Despite its name and association with Monaco, the venue is technically across the border in France.
Readers sometimes confuse Nadal’s Monte Carlo record with his 10 Italian Open titles or 14 French Open titles. Another related figure is his 46-match winning streak at Monte Carlo from 2005 to 2013. The question asks for tournament victories, not consecutive wins or finals, so 11 is the canonical answer.