Jerez de la Frontera (Spanish pronunciation: [xeˈɾeθ ðe la fɾonˈteɾa]) or simply Jerez, also cited in old English-language sources as Xeres, is a city and municipality in the province of Cádiz in the autonomous community of Andalusia, Spain. Located in southwestern Iberia, it lies on the Campiña de Jerez, an inland low-land plain crossed by the Guadalete river, midway between the Atlantic Ocean, the Guadalquivir river and the western reaches of the Subbaetic System.

As of 2020^[update], with 213,105 inhabitants, Jerez is the most-populated municipality in the province of Cádiz. Its municipality covers an area of 1,188.14 km² (458.74 sq mi) and includes Los Alcornocales Natural Park.

Winegrowing has long been, particularly upon the transition to modern agro-extractivism in the mid 18th century, the main drive of the economy of Jerez. During the 19th century, the local wine Sherry was overwhelmingly produced for foreign export, catering to the British market in the first place. Throughout this century the city earned a reputation as a paradigm for large landowners, high social inequality, and the winery-related identity.

Since 1987, Grand Prix motorcycle racing has been held at the Circuito de Jerez in early May. The circuit has also hosted several Formula One Grands Prix, including the 1997 European Grand Prix, which decided the 1997 Formula One World Championship. Other festivals in the city include the Feria de Jerez and the Holy Week.

The classical Latin name of Asta Regia, unrelated to the present name, referred to an ancient city now found within Mesas de Asta, a rural district approximately 11 km (6.84 mi) from the center of Jerez.

The current Spanish-language name came by way of the Arabic-language name شريش Sharīsh, used during the Muslim period in Iberia. The placename was rendered as Xerez or Xerés (Old Spanish pronunciation: [ʃeˈɾet͡s̻, ʃeˈɾes̺]) in old Romance sources; hence the name of the famous fortified wine, sherry. Frontera ('frontier') referred to its location on the border between the Moorish and Christian regions on the Iberian Peninsula during the 13th century.^{[citation needed]} Upon the Modern-era readjustment and simplification of Spanish-language sibilant phonemes (including /ʃ/ changed into /x/) the spelling of the place name ended up being changed accordingly.

The old spelling Xerez survived in several foreign languages and led to the name given to sherry: Portuguese Xerez [ʃɨˈɾɛʃ], Catalan Xerès [ʃəˈɾɛs], English sherry /ˈʃɛri/, French xérès [ɡzeʁɛs]. The city's main football team continues to use the old spelling, Xerez.

Traces of human presence in the area date from the upper Neolithic, and humans have inhabited Jerez de la Frontera since at least the Copper or Neolithic Age, but the identity of the first natives remains unclear. The first major protohistoric settlement in the area (around the third millennium BC) is attributed to the Tartessians. Jerez later became a Roman city under the name of Asta Regia (located 8 km further north at Cortijo el Rosario).