Simon played at the first grand slam of the year, the 2009 Australian Open, as the sixth seed, winning against Pablo Andújar in the first round.
He also competed with Jérémy Chardy as his partner in the doubles, but the pair was defeated by Daniel Nestor and Nenad Zimonjić in the first round.
He competed with fellow players Jo-Wilfried Tsonga and Jérémy Chardy, forming the French team at the ARAG World Team Cup in Düsseldorf. He entered Roland Garros as the seventh seed and defeated Wayne Odesnik in five sets in the first round, and Robert Kendrick in straight sets.
This resulted in an entry into the top 15, three ranks behind the French no. Simon participated in the 2008 Summer Olympics in Beijing, playing in the singles for France alongside Paul-Henri Mathieu, Michaël Llodra, and Gaël Monfils.
He played doubles with Monfils, but lost in the first round to the Indian team of Bhupathi and Paes.
During his third-round match, he also injured his right knee.
Although he finished the match, this knee injury turned into a chronic problem that bothered him for a long time.
During 2004, he saw three wins in France and another in Algeria.
In January 2005, he won his first ATP Challenger hard court tournament in Nouméa, New Caledonia, and defended it the following year. 113, Simon made his Grand Slam debut at the 2005 French Open, losing in the first round to Olivier Patience in four sets.
The following week, he competed at the Rogers Cup in Toronto, including a win over world no.
1 Roger Federer in the second round, before losing in the semifinals to German veteran Nicolas Kiefer.
Simon was leading in the first two sets before Monfils retired due to a wrist injury. 1 Rafael Nadal in the quarterfinals, where he was dispatched, although he had two set points in the second set.