In Sunday’s final, sixth seed Berdych will play the winner of the second semi-final between former champions Novak Djokovic and Rafael Nadal, who meet later for a record 43rd time.
Berdych won the opening set over Monfils, who knocked out Roger Federer in the third round and Grigor Dimotrov in the quarter-finals, in just 23 minutes.
The Czech emerged with a 2-1 lead as the second set began with three straight breaks and took victory in 68 minutes.
Berdych will be playing in his fourth Masters 1000 final and first since losing to Federer in Madrid three years ago.