See main article: 2008 Masters Series Monte-Carlo.
Three-time defending champion Rafael Nadal defeated Roger Federer in a rematch of the previous two years' finals, 7–5, 7–5 to win the singles tennis title at the 2008 Monte-Carlo Masters. For the second year in a row, he did not lose a single set in the entire tournament.
The top eight seeds receive a bye into the second round.