Tilapia ( /tɨˈlɑːpiə/ ti-LAH-pee-ə), is the common name for nearly a hundred species of cichlid fish from the tilapiine cichlid tribe. Tilapia inhabit a variety of fresh water habitats, including shallow streams, ponds, rivers and lakes. Historically, they have been of major importance in artisan fishing in Africa and the Levant, and are of increasing importance in aquaculture. Tilapia can become problematic invasive species in new warm-water habitats, whether deliberately or accidentally introduced, but generally not in temperate climates due to their inability to survive in cool waters, generally below 70 °F (21 °C); see tilapia as exotic species.

The common name tilapia is based on the name of the cichlid genus Tilapia, which is itself a latinization of thiape, the Tswana word for "fish".Scottish zoologist Andrew Smith named the genus in 1840.

Tilapia go by many names. The name "St. Peter's fish" comes from the story in the Gospel of Matthew about the apostle Peter catching a fish that carried a coin in its mouth, though the passage does not name the fish. While the name also applies to Zeus faber, a marine fish not found in the area, a few tilapia species (Sarotherodon galilaeus galilaeus and others) are found in the Sea of Galilee, where the author of the Gospel of Matthew accounts the event took place. These species have been the target of small-scale artisanal fisheries in the area for thousands of years. In some Asian countries including the Philippines, large tilapia go by pla-pla while the smaller types are just tilapia.