Colmar-Berg (; ) is a commune in central Luxembourg, in the canton of Mersch. It comprises the localities of Colmar and Berg, situated on either bank of the river Attert, as well as Welsdorf.
Colmar-Berg is the site of the Grand Duke of Luxembourg's principal residence, Berg Castle. It is also the site of a Goodyear tyre factory.
The commune was known as simply "Berg" until 25 March 1991.
Luxembourg's national drivers' training center () is also in Colmar-Berg. Each person receiving a driver's license in Luxembourg for the time is required to follow a day-long training course there between three months and two years after the obtention of their license in order to receive a permanent license.