The Jaffa riots (Hebrew: מאורעות תרפ"א ‎) were a series of violent riots in Palestine on May 1–7, 1921, which began as a fight between two Jewish groups but developed into an attack by Arabs on Jews during which many were killed. The rioting began in Jaffa and spread to other places.

On the night of 1 May 1921, the Jewish Communist Party (precursor of the Palestine Communist Party) distributed Arabic and Yiddish fliers calling for the toppling of British rule and the establishing a "Soviet Palestine". The party announced its intention to parade from Jaffa to neighbouring Tel Aviv to commemorate May Day. On the morning of the parade, despite a warning to the 60 members present from one of Jaffa's most senior police officers, Toufiq Bey al-Said, who visited the party's headquarters, the march headed from Jaffa to Tel Aviv through the mixed Jewish-Arab border neighbourhood of Manshiyya.

Another large May Day parade had also been organized for Tel Aviv by the rival socialist Ahdut HaAvoda group, with official authorization. When the two processions met, a fistfight erupted.Police attempted to disperse the about 50 communist protestors, and Muslims and Christians intervened to help the police against the Jews. A general disturbance quickly ensued and spread to the southern part of town.

Jaffa (English pronunciation: /ˈdʒæfə/, /ˈdʒɑːfə/;Hebrew: יָפוֹ‎‎,  Yāfō (help·info); Arabic: يَافَا‎  Yāfā (help·info); Latin: Joppe; also Japho, Joppa (transliteration from the Greek "Ιόππη") is an ancient port city believed^{[by whom?]} to be one of the oldest in the world. Jaffa was incorporated with Tel Aviv in 1950 creating the city of Tel Aviv-Yafo, Israel. Jaffa is famous for its association with the biblical story of the prophet Jonah.

The name of the city is mentioned in 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. An outcropping of rocks near the harbor is reputed to have been the place from which Andromeda was rescued by Perseus. 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.