Chayote (/tʃaɪˈoʊteɪ/; previously placed in the obsolete genus Sechium), also known as christophine, mirliton, güisquil, and choko, is an edible plant belonging to the gourd family, Cucurbitaceae. This fruit was first cultivated in Mesoamerica between southern Mexico and Honduras, with the most genetic diversity available in both Mexico and Guatemala. It is one among dozens of foods introduced to the Old World during the Columbian Exchange. At that time, the plant spread to other parts of the Americas, ultimately causing it to be integrated into the cuisine of many Latin American nations.

The chayote fruit is mostly used cooked. When cooked, chayote is usually handled like summer squash; it is generally lightly cooked to retain the crispy consistency. Raw chayote may be added to salads or salsas, most often marinated with lemon or lime juice, but is often regarded as unpalatable and tough in texture. Whether raw or cooked, chayote is a good source of Vitamin C.

Although most people are familiar only with the fruit as being edible, the root, stem, seeds and leaves are edible as well. The tubers of the plant are eaten like potatoes and other root vegetables, while the shoots and leaves are often consumed in salads and stir fries, especially in Asia.

The fruit goes by many English-language names around the world. "Chayote", the common American English name of the fruit (outside of Louisiana) is from the Spanish word chayote, a derivative of the Nahuatl word chayohtli (pronounced [t͡ʃaˈjoʔt͡ɬi]). The Nahuatl-derived name is preserved in the Philippines, where it is known as sayote or tsayote. It is also known as güisquil in Guatemala, El Salvador, and pataste in Honduras.

In Louisiana and Haiti it is known as "mirliton" (English: /ˈmɪərlətɒn/) also spelled "mirleton" or "merleton" in the United Kingdom. The r is often silent, e.g. Cajun me-lay-taw).^{[failed verification]}

In the eastern Caribbean, the United Kingdom and Ireland, it is known as "christophine" or "christophene" (from French, a reference to Christopher Columbus).^{[verification needed]}

In other parts of the world, the English name is often "cho cho", "chouchou" (e.g. in Mauritius), or a variant thereof (e.g. "chow-chow" in India and Sri Lanka, "chuchu" in Brazil, and "chocho" in Jamaica). This name may have originated from Pidgin English for "chayote". In Nepal it is known as Es-kus.

In Australia, New Zealand and Singapore, it is known as "choko". The name is derived from Cantonese, from Chinese immigrants to Australia and New Zealand in the late 19th century.