in august 2008, šimić moved to as monaco. he made his ligue 1 debut on 23 august 2008 in monaco's 1–1 draw at home to sm caen, playing the entire match and assisting frédéric nimani for the opening goal. he went on to establish himself as a regular at the club, making a total of 26 league appearances before being sent off against le havre in april 2009. he lost his place as a regular in the team after that, making no appearances since monaco's final league match of the 2008–09 season, a goalless draw at paris saint-germain.