Perhaps nothing is better known as a staple of Cajun cuisine than gumbo, a spicy, hearty stew or soup whose name literally means "okra". Called one of the greatest contributions of Louisiana Cajun kitchens to American cuisine, it came to that state with the first French settlers, who loved bouillabaisse, a highly seasoned French stew. Unable to find their usual ingredients to make bouillabaisse, they substituted local ingredients such as shrimp, fish, and okra. After a century mixing with Spanish, African, and native cuisine in the region, the step was no longer recognizable as its French precursor and was instead something completely new – gumbo.

Still extremely common in Louisiana, gumbo is also found all along the Gulf of Mexico, and is often eaten in the cooler months, when the extended cooking required to make the usually large batches of the dish will not heat up the room to uncomfortable levels.

Gumbo consists of two main components – rice and broth. The two are mixed together only for serving, and while new rice must be prepared daily, broth can be frozen and saved for future consumption.

Rice for gumbo is usually white or parboiled rice steamed or boiled with salt or a touch of white vinegar for flavor. There is some dispute over the proper ratio of rice to gumbo – "damp rice," for those who like a lot of rice with their broth, and, on the opposite extreme, only a modicum of rice. In some areas, it is also common to add potato salad to the gumbo, either with or without rice.

The broth comes in several varieties. One of the most common is seafood, containing crab, oysters and/or shrimp. Equally common is chicken gumbo with the Cajun sausage called audouille. There is also duck and oyster gumbo, as well as a variety of gumbos made with other fowl, such as quail or turkey. Rabbit can be used for gumbo, as can the Cajun smoked pork known as Tasso. Gumbo z’herbes (from the French gumbo aux herbes), gumbo of smothered greens thickened with roux, also exists, and was commonly eaten during Lent, when meat was traditionally forbidden by the Church.

Gumbo was originally made with okra, and some, especially in Southeast Louisiana would argue that anything made without okra cannot rightly be called gumbo. Okra gumbos usually feature lighter meats, such as chicken or shrimp, and the okra is cut into pieces and simmered in the pot along with the meat and the three spices that form the so-called "Holy Trinity" of Cajun cooking – onion, celery, and bell pepper. Other spices, and rarely processed meats such as sausage, are then added to the mix. Contrary to popular belief, it is frowned upon for a chef to make Cajun cooking overly hot or peppery – these are left to the diners themselves if they wish to add more spices later.

Gumbo can also be made with a roux base, which has a much stronger taste and takes any sort of meat. Roux by itself is often very dark, though it can be combined with okra to make a lighter stock. File, a powder made of dried and ground sassafras, can also be used as a base for gumbo, though it is never, under any circumstances, combined with okra. Originally, it was used as a substitute when okra was not in season. In modern times, it is commonly added as a powder to a roux based gumbo.