He was born in Riyadh, Saudi Arabia. His father was a wealthy businessman with close ties to the Saudi Royal family. His father originally comes from Hadhramaut, on the south coast of Yemen.

Osama Muhammed bin Laden was born in Riyadh, Saudi Arabia In a 1998 interview, later televised on Al Jazeera, he gave his birth date as March 10, 1957. His father, the late Muhammed Awad bin Laden, was a wealthy businessman with close ties to the Saudi royal family.[10] Before World War I, Muhammed, poor and uneducated, emigrated from Hadhramaut, on the south coast of Yemen, to the Red Sea port of Jeddah, Saudi Arabia, where he began to work as a porter. Starting his own business in 1930, Muhammed built his fortune as a building contractor for the Saudi royal family during the 1950s. There is no definitive account of the number of children born to Muhammed bin Laden, but the number is generally put at 55. Various accounts place Osama as his seventeenth son. Muhammed bin Laden was married 22 times, although to no more than four women at a time per Sharia law. Osama was born the only son of Muhammed bin Laden's tenth wife, Hamida al-Attas, nee Alia Ghanem,[11] who was born in Syria.[12] (Wikipedia) I cannot find any information about his ancestry, sorry, but his father had the title Sheikh, which is the title for a tribal leader. Presumably, the family had ties to one of the central dynasties of one of the many Arab tribes of the peninsula. It is very difficult for most Arabs to trace ancestry firstly because they have no system of surnames, using a father to son naming system. We can presume that Osama's grandfather might have been called Laden, as bin Laden means son of Laden. But, it is equally possible that Laden could refer to an ancestor of some status, not a grandfather. The other problem of descent is that it is sometimes unclear who the mothers of particular children are, particularly in wealthy families where multiple marriages occur, and divorce is common. However, female descents are considered unimportant in Arabic culture, unless the woman is a "saida", descendant of the prophet.