The 2009 Monte-Carlo Rolex Masters was a men's tennis tournament for professional players held from 11 April until 19 April 2009, on outdoor clay courts. It was the 103rd edition of the annual Monte Carlo Masters tournament, which was sponsored by Rolex for the first time and was classified as an ATP World Tour Masters 1000 tournament on the 2009 ATP World Tour. It took place at the Monte Carlo Country Club in Roquebrune-Cap-Martin, France, near Monte Carlo, Monaco.

Rafael Nadal Parera is a Spanish professional tennis player. Nadal has been ranked world No. 1 in singles by the Association of Tennis Professionals (ATP) for 209 weeks, and has finished as the year-end No. 1 five times. Nadal has won 22 Grand Slam men's singles titles, including a record 14 French Open titles. He has won 92 ATP-level singles titles, including 36 Masters titles and an Olympic gold medal, with 63 of these on clay courts. Nadal is one of only two men to complete the Career Golden Slam in singles. His 81 consecutive wins on clay constitute the longest single-surface win streak in the Open Era.