Cinsault or Cinsaut (pronounced "san-so") is a red wine grape, whose heat tolerance and productivity make it the fourth most widely-planted grape variety in France. Cinsaut is especially planted in Languedoc and Roussillon. It is often blended with grapes of the Mediterranean regions to add softness and bouquet.

Cinsault is often blended with Grenache and Carignane. Synonyms include Cinq-saou, Black Malvoisie (in California) Boudales, Plant d'Arles, Picardin noir, Morterille noire, Cuviller, and Hermitage (in South Africa and parts of Europe).

It is sometimes confusingly referred to as Oeillade when sold as a table grape. The true Oeillade with very different leaves is no longer cultivated.

The grape, under the name Ottavianello, has also long been cultivated in Puglia, the “heel” of Italy, where after having fallen into almost complete neglect[1] it has begun to attract the attention of winemakers interested in reviving old varieties.[2]

Cinsault is crossed with the Pinot Noir grape to give the Pinotage grape variety.