Roussanne is a white wine grape grown originally in the Rhône wine region in France, where it is often blended with Marsanne. It is the only other white variety, besides Marsanne, allowed in the northern Rhône appellations of Crozes-Hermitage AOC, Hermitage AOC and Saint-Joseph AOC. In the southern Rhône appellation of Châteauneuf-du-Pape AOC it is one of six white grapes allowed, where it may be blended into red wines. Roussanne is also planted in various wine-growing regions of the New World, such as California, Washington, Texas, South Africa and Australia as well as European regions such as Crete, Tuscany and Spain.

The berries are distinguished by their russet color when ripe—roux is French for the reddish-brown color russet, and is probably the root for the variety's name. The aroma of Roussanne is often reminiscent of a flowery herbal tea. In warm climates, it produces wines of richness, with flavors of honey and pear, and full body. In cooler climates it is more floral and more delicate, with higher acidity. In many regions, it is a difficult variety to grow, with vulnerability to mildew, poor resistance to drought and wind, late and/or uneven ripening, and irregular yields.