Ceviche is a traditional Peruvian dish made from raw fish or seafood marinated in citrus juices, primarily lime or bitter orange. The acidic marinade denatures the proteins in the fish, giving it the appearance and texture of being cooked without heat. The dish is typically seasoned with salt, onions, and chili peppers, and is commonly served with side dishes such as boiled corn (choclo), slices of cooked sweet potato (camote), and lettuce.

Historical evidence suggests that ceviche was consumed in Peru as far back as 2,000 years ago by ancient civilizations such as the Moche. Archaeological findings indicate that early Peruvians preserved fish with fermented fruit juices similar to the technique used today. The use of lime and onions likely became common after the arrival of Spanish colonizers, who brought citrus fruits and onions to the region in the 16th century. Before this, the local people may have used chicha, a fermented corn beverage, as the marinating agent.

The word "ceviche" has several spelling variants, including seviche and cebiche, but "ceviche" is the most widely accepted in Peru. The origins of the name are debated; some theories link it to the Spanish word "escabeche" (marinated food), while others trace it to the Quechua term "siwichi," meaning fresh or tender fish.

In Peru, ceviche was traditionally eaten in the morning or at lunchtime. The national importance of the dish was formalized in 2008, when the Peruvian government declared June 28 as National Ceviche Day. In 2004, ceviche was declared part of Peru’s National Cultural Heritage. Ceviche has spread across Latin America, including variations in Ecuador, Mexico, and Chile, but the Peruvian style is recognized for its distinct use of ingredients and preparation methods.