Jeddah is a governorate and the largest city in Mecca Province, Saudi Arabia, and the country's second largest city after Riyadh, located along the Red Sea coast in the Hejaz region. Jeddah is the commercial center of the country. It is not known when Jeddah was founded, but Jeddah's prominence grew in 647 when the Caliph Uthman made it a travel hub serving Muslim travelers going to the holy city of Mecca for Islamic pilgrimage. Since those times, Jeddah has served as a gateway for millions of pilgrims who have arrived in Saudi Arabia.

With a population of about 3,751,722 people as of 2022, Jeddah is the largest city in Mecca Province, the largest city in Hejaz, the second-largest city in Saudi Arabia (after the capital Riyadh), and the ninth-largest in the Middle East. It also serves as the administrative centre of the OIC. Jeddah Islamic Port, on the Red Sea, is the thirty-sixth largest seaport in the world and the second-largest and second-busiest seaport in the Middle East (after Dubai's Port of Jebel Ali).

Jeddah is the principal gateway to Mecca Sharif, the holiest city in Islam, 65 kilometers (40 mi) to the east, while Medina, the second-holiest city, is 360 kilometers (220 mi) to the north. Economically, Jeddah is focusing on further developing capital investment in scientific and engineering leadership within Saudi Arabia, and the Middle East. Jeddah was ranked fourth in the Africa, MiddIe East, and 'stan countries region in the Innovation Cities Index in 2009.

Jeddah is one of Saudi Arabia's primary resort cities and was named a Beta world city by the Globalization and World Cities Research Network (GaWC). Given the city's close proximity to the Red Sea, fishing and seafood dominate the food culture unlike other parts of the country. In Arabic, the city motto is "Jeddah Ghair", which translates to "Jeddah is different".

There are at least two etymologies of Jeddah, according to Jeddah Ibn Al-Qudaa'iy, the chief of the Quda'a clan. The more common account has it that the name is derived from جدة Jaddah, the Arabic word for "grandmother". According to folk belief, the Tomb of Eve, who is considered the grandmother of humanity, is located in Jeddah.

The Maghrebi traveler Ibn Battuta visited Jeddah during his world trip in around 1330. He wrote the name of the city into his diary as "Jiddah".

The British Foreign and Commonwealth Office and other branches of the British government formerly used the older spelling of "Jedda", contrary to other English-speaking usages, but in 2007, it changed to the spelling "Jeddah".

T. E. Lawrence felt that any transcription of Arabic names into English was arbitrary. In his book Revolt in the Desert, Jeddah is spelled in three different ways on the first page alone.