He was born the small Akçakaya village, in Kayseri in central Anatolia, Turkey.
In 1921, a couple of years after the death of his father, the then fifteen-year-old youngster left his hometown and walked all the way to Adana to seek his fortune.
In the following years, he founded Oralitsa (1954), a roofing material factory, and Aksigorta (1960), an insurance company.
In 1928, he married Sadıka (1910–1988), who bore him six sons, İhsan (1931–1979), Sakıp (1933–2004), Hacı (1935–1998), Şevket (1936–2021), Erol (born 1938) and Özdemir (1941–1996).
Hacı Ömer Sabancı and his family moved to Istanbul after purchasing, in 1951, a mansion known as Atlı Köşk (English: Equestrian Villa) on the European shore of Bosphorus in Emirgan.