Kirschwasser, often known simply as Kirsch, is a clear brandy made from double distillation of the fermented juice of a small black cherry. It is colorless because it is not aged in wood. The cherries used recently can be either sweet or sour, but in the past the sour morello cherry was used with the pit crushed down. The morello cherry was originally grown all around the Black Forest in southern Germany so that is believed to be where the drink originated from.

Clear alcoholic beverages made from distilled fruit juices are common in southern Germany, western Austria and German-speaking Switzerland. In addition to Kirschwasser, typical drinks of this sort include Obstler (distilled from apple, or a mixture of apple and pear), Zwetschgenwasser (plums) and Himbeergeist (raspberries). Such spirits are also distilled in France and French-speaking Switzerland, where they are known as eau de vie ("water of life", the same term that is the root of the words akvavit and whisky).

Unlike cherry liqueurs, Kirschwasser is not sweet. The best Kirschwassers have a highly refined taste with subtle flavors of cherry. Kirschwasser can be found in such mixed drinks as the Lady Finger, Florida Cocktail, and Black Forest.

The name is German and means "cherry water". Kirsch dating back to vulgar Latins ceresia, meaning cherry, and Wasser from old high German wassar meaning water.

Kirschwasser is sometimes drunk by itself. Traditionally, it is served cold in a very small glass and taken as a apéritif. However, people in the German-speaking regions where Kirschwasser originates would more usually serve it after dinner, and high-quality Kirschwasser would more likely be served at room temperature or warmed by the hands, like other brandies.

"Kirsch" is an essential ingredient in Swiss cheese fondue recipes. Its alcoholic content is 40%-50% (80-100 proof). About ten kilograms (about 22 pounds) of cherries go into making a 750 ml bottle of Kirschwasser.

It is also used in traditional German Schwarzwälder Kirschtorte ( Black Forest gateau) that is believed to have originated from the 16th century.

Kirschwasser is also used in some recipes, for example in Kugelhopf, Black Forest and Black Russian Cakes.