Riesling is a white grape variety and varietal appellation of wines grown historically in Alsace (France), Austria, Germany (see German wine), and northern Italy. It is suited to relatively cool climates. Riesling wines from Germany are traditionally sweet to medium sweet, but those from Alsace and Austria tend to be dry (sec) or just off-dry (demi-sec). Dry German Rieslings are increasingly popular in Germany, and are labeled as trocken. Other names for true Riesling are Johannisberg Riesling (named after the famed Schloss Johannisberg ) and White Riesling . Many grapes that incorporate the name Riesling are not true Riesling. For example, Grey Riesling is actually Trousseau Gris , an unrelated but not entirely dissimilar grape.

Riesling is also grown in the New World, notably Australia where the grape produces a distinctive crisp, dry and fruity wine. Peter Lehmann is notable for the quality of his Australian riesling. In North America, Riesling is usually grown in cooler regions, such as northern California, New York, Michigan and Ontario, and shows promise in the Pacific Northwest. It is also grown in cooler regions of New Zealand and South Africa, and the quality is improving significantly in the New World as more suitable sites are found, better quality vines are planted, and the vines age.

Riesling is one of the grape varieties considered to best express the terroir of the place that it is grown, much more so than many other white grapes.

The most highly regarded wines made from Riesling are late harvest dessert wines, produced by letting the grapes hang on the vines well past normal picking time. Through evaporation caused by the fungus Botrytis cinerea or by freezing, as in the case of ice wine (in German, Eiswein), water is removed and the resulting wine offers profoundly richer layers on the palate. These concentrated wines have more sugar (in extreme cases hundreds of grams per liter), more acid (to give balance to all the sugar), more flavors, etc. Due to its concentration, late-harvest Riesling is among the longest-lived of all wines.

Riesling is a very versatile wine to have with food, because of its balance of sugar and acid. It can pair with white fish just like a dry wine, or with pork, and it is one of the few wines that can stand up to Thai and Chinese cuisine. Riesling's typical aromas are of flowers, tropical fruits, and mineral stone (such as slate or quartz), although, with time, the wine acquires an oily character that may be immediately arresting to new drinkers of Riesling. It is almost never oaked, which tends to lighten its profile and increase its suitability with many foods.