The 2005 Monte Carlo Masters was a tennis tournament played on outdoor clay courts. It was the 99th edition of the event and was part of the ATP Masters Series of the 2005 ATP Tour. It took place from April 11 through April 17, 2005.
The men's singles was headlined by World No. 1 Roger Federer, Marat Safin and Tim Henman. Other top seeds were Gastón Gaudio, Carlos Moyà, Guillermo Coria, Joachim Johansson and Ivan Ljubičić.
Rafael Nadal def. Guillermo Coria, 6–3, 6–1, 0–6, 7–5.
Leander Paes / Nenad Zimonjić def. Bob Bryan / Mike Bryan, walkover.