Khadjibey (Turkish: Hacıbey) was a fortress and a haven by the Gulf of Odessa, in the location of the modern city of Odessa, Ukraine. Other known spellings include Khadzhibey, Khadjibei, Hajibey, Khacdjibei, Hacıbey, Hocabey, Gadzhibei, Chadžibėjus, Hacıbey, Codjabey, Kachybey, Kotsiubey, Kotsiubiiv.
By one hypothesis, it was named after Hacı I Giray. Polish historian Marian Karol Dubiecki suggested the connection of the name of the fortress with the Polish roots linking it with the surname Kociuba,  an opinion criicized by Vasili Nadler.
Nadler suggested that a Tatar settlement existed on the site by 14th century but was ceded in the early 15th century to the Polish–Lithuanian Commonwealth. An early mention of a "port Kaczubyeiow" dated by 1415 is given by Jan Długosz in his Historiae Polonicae. However it is argued that Długosz erred and the described events (gifting grain by king Władysław II Jagiełło to besieged Constantinople) are reliably documented to be happened in 1413.
In 1480 the fortress was captured by the Ottoman Empire. In 1764 the Ottomans reinforced their position by building the Yeni Dünya fortress nearby; it was included in the province of Silistra Eyalet. In 1789, during the Russo-Turkish War, the Russian army took the fortress and settlement and in 1792 and the territory was transferred to the Russian Empire.
- W. Jakowicki - "Przewodnik po Odessie (z planem miasta) i opis podróży z Warszawy do Odessy" Warszawa 1910
- Vasili Nadler, Одесса в первые эпохи ее существования, Одесса, 1893. Reprinted: Odessa, Optimum, 2007, ISBN 966-344-152-6.
- Jan Długosz, Historiae Polonicae, p 367
- Quote: "Wladislaus antem Poloniae Rex, necessitati corum satagens pia commiseratione succurere, petitam frumenti quantitatem dat et largitur, et in portu suo Regio Kaczubyeiow, per cos recepiendam, consignat, Datis autem Alexandre Moldauiae Voieuedae et suae consorti donis reuersalibus, et Anna Regina Cracouiam remissa, processit in Camyeniecz..."