Harissa is a Tunisian hot red sauce or paste made from chili peppers (often smoked) and garlic, often with coriander, cumin, caraway, and/or olive oil. It may also contain tomatoes. It somewhat resembles sambal and chili sauce. One well-known and expensive variety, "rose harissa" also includes rose petals.

Harissa is used both as a condiment and as an ingredient. It has been described as the most important item in Tunisian cuisine, and can be found in other cuisines of North Africa, such as those of Morocco and Algeria.

The sauce is sold in tubes, jars and cans, and often eaten with couscous, with pasta, on sandwiches, and in soup. Harissa paste can be used as a meat rub.