The 1977 Monte Carlo Open was a men's tennis tournament played on outdoor clay courts at the Monte Carlo Country Club in Roquebrune-Cap-Martin, France. The tournament was part of the World Championship Tennis (WCT) tour. It was the 71st edition of the event and was held from 4 April through 10 April 1977. Björn Borg won the singles title and the accompanying $30,000 first-prize money.