Jaffa (Hebrew: יָפוֹ‎, About this sound Yāfō (help·info); Arabic: يَافَا‎, About this sound Yāfā (help·info); Latin: Joppe; also Japho, Joppa as transliteration from the Greek "Ιόππη") is an ancient port city believed to be one of the oldest in the world. Jaffa is now part of Tel Aviv which is why the city's full name is Tel Aviv-Jaffa, Israel. The name of the city is supposed to be mentioned in the Egyptian sources and the Amarna Letters as Yapu. There are several legends about the origin of the name Jaffa. Some say it is named for Japheth, one of the sons of Noah, who built it after the Great Flood.[citation needed] The Hellenist tradition links the name to "Iopeia", which is Cassiopeia, the mother of Andromeda. Pliny the Elder associates the name with Jopa, the daughter of Aeolus, god of wind.

The Arab geographer Al-Muqaddasi mentions it under the name Yaffa, which is used by Arabic speakers today.

Tel Yafo (Jaffa Hill) rises to a height of 40 meters (130 ft) and offers a commanding view of the coastline. Hence its strategic importance in military history. The accumulation of debris and landfill over the centuries made the hill even higher.

Archaeological evidence shows that Jaffa was inhabited some 7,500 years BCE. Jaffa's natural harbor has been in use since the Bronze Age.

Jaffa is mentioned in an Ancient Egyptian letter from 1470 BCE, glorifying its conquest by Pharaoh Thutmose III, who hid armed warriors in large baskets and gave the baskets as a present to the Canaanite city's governor. The city is also mentioned in the Amarna letters under its Egyptian name Ya-Pho, ( Ya-Pu, EA 296, l.33). The city was under Egyptian rule until around 800 BCE. Jaffa is mentioned four times in the Hebrew Bible, as one of the cities given to the Hebrew Tribe of Dan (Book of Joshua 19:46), as port-of-entry for the cedars of Lebanon for Solomon's Temple (2 Chronicles 2:16), as the place whence the prophet Jonah embarked for Tarshish (Book of Jonah 1:3) and as port-of-entry for the cedars of Lebanon for the Second Temple of Jerusalem (Book of Ezra 3:7). Jaffa is mentioned in the Book of Joshua as the territorial border of the Tribe of Dan, hence the nowadays term "Gush Dan", used for the center of the coastal plain. Many descendants of Dan lived along the coast and earned their living from shipmaking and sailing. In the "Song of Deborah" the prophetess asks: "דן למה יגור אוניות": "Why doth Dan dwell in ships?"
After the Canaanite and Philistean domination, King David and his son King Solomon conquered Jaffa and used its port to bring the cedars used in the construction of the First Temple from Tyre. The city remained often in Jewish hands even after the split of the Kingdom of Israel. In 701 BCE, in the days of King Hezekiah (חזקיהו), Sennacherib, king of Assyria, invaded the region from Jaffa. After a period of Babylonian occupation, under the Persian rule, Jaffa was governed by Phoenicians from Tyre. Then it knew the presence of Alexander the Great troops and later became a Seleucid Hellenized port until it was taken over by the Maccabean rebels (1 Maccabees x.76, xiv.5) and the refounded Jewish kingdom. During the Roman repression of the Jewish Revolt, Jaffa was captured and burned by Cestius Gallus. The Roman Jewish historian Josephus (Jewish War 2.507-509, 3:414-426) writes that 8,400 inhabitants were massacred. Pirates operating from the rebuilt port incurred the wrath of Vespasian, who razed the city and erected a citadel in its place, installing a Roman garrison there.

The boundaries of Tel Aviv and Jaffa became a matter of contention between the Tel Aviv municipality and the Israeli government during 1948. The former wished to incorporate only the northern Jewish suburbs of Jaffa, while the latter wanted a more complete unification.The issue also had international sensitivity, since the main part of Jaffa was in the Arab portion of the United Nations Partition Plan, whereas Tel Aviv was not, and no armistice agreements had yet been signed. On 10 December 1948, the government announced the annexation to Tel Aviv of Jaffa's Jewish suburbs, the ex-Arab neighborhood of Abu Kabir, the ex-Arab village of Salama and some of its agricultural land, and the Jewish 'Hatikva' slum. On 25 February 1949, the abandoned Arab village of Sheikh Muanis was also annexed to Tel Aviv. On 18 May 1949, the former Arab neighborhood of Manshiya and part of Jaffa's central zone were added, for the first time including land that had been in the Arab portion of the UN partition plan. The government decided on a permanent unification of Tel Aviv and Jaffa on 4 October 1949, but the actual unification was delayed until 24 April 1950 due to concerted opposition from Tel Aviv's mayor Israel Rokach. The name of the unified city was Tel Aviv until 19 August 1950, when it was renamed as Tel Aviv-Yafo in order to preserve the historical name Jaffa. Modern Jaffa has a heterogeneous population of Jews, Christians, and Muslims. Parts of the Old City have been renovated, turning Jaffa into a tourist attraction featuring old restored buildings, art galleries, theaters, souvenir shops, restaurants, sidewalk cafes and promenades. Beyond the Old City and tourist sites, many neighborhoods of Jaffa are poor and underdeveloped. However, real-estate prices have risen sharply due to gentrification projects in al Ajami and Lev Yafo. The municipality of Tel Aviv-Jaffa is currently working to beautify and modernize the port area, and are expanding the boardwalk along the sea from Bat Yam to Tel Aviv. They are also constructing a light rail that will travel from Bat Yam to Petach Tikvah and throughout the Gush Dan territory.