Ambt Montfort ( pronunciation) is a former municipality in the Dutch province of Limburg.
In 1991, the municipalities of Montfort, Posterholt, Reutje and Sint Odiliënberg merged. The original name of the merged municipality was "Posterholt", but it was changed in "Ambt Montfort" in 1994. On January 1, 2007, Ambt Montfort merged into the municipality of Roerdalen.