Budjak or Budzhak (Russian, Ukrainian, and Bulgarian: Буджак; Turkish: Bucak, Romanian: Bugeac) is a historical region in the Odessa Oblast (province) of Ukraine. Lying along the Black Sea between the Danube and Dniester rivers, this multi-ethnic region of 13,188 km² was the southern part of Bessarabia. The region is bordered in the north and west by Moldova, in the south by Romania and in the east by the Black Sea.
Historically, Budjak was a smaller, southeastern steppe region of Moldavia. Bordered by the northern Trajan's Wall at its north end, by the Danube river and Black Sea to its south, by Tigheci Hills (just east of the Prut River) to the west, and Dniester river to the east, it was known as historic Bessarabia until 1812, when this name was given to the larger region situated between the two rivers, including Budjak. As used in Middle Ages, the term might (if referred to the geographical area) or might not (if referred to the area predominated by Nogai Tatars) include Cetatea Albă, Chilia and Izmail counties. After the Soviet occupation of Bessarabia in 1940, its southern part that was included in the Ukrainian SSR and did not form Moldavian SSR, became known as Budjak, thus being slightly smaller than the historical term.