Ratatouille is a French Provençal dish of stewed vegetables which originated in Nice, and is sometimes referred to as ratatouille niçoise (French: [niswaz]). Recipes and cooking times differ widely, but common ingredients include tomato, garlic, onion, courgette (zucchini), aubergine (eggplant, brinjal), capsicum (bell pepper), and some combination of leafy green herbs common to the region.

The word ratatouille derives from the Occitan ratatolha and is related to the French ratouiller and tatouiller, expressive forms of the verb touiller, meaning “to stir up”. From the late 18th century, in French, it merely indicated a coarse stew. Modern ratatouille uses tomatoes as a foundation for sautéed garlic, onion, zucchini, aubergine (eggplant), bell pepper, marjoram, fennel and basil. Instead of basil, bay leaf and thyme, or a mix of green herbs like herbes de Provence can be used. The modern version does not appear in print until c.1930.