Barack Hussein Obama (1936 ? 24 November 1982) was a Kenyan senior governmental economist, and father of former Illinois Senator and President-elect of the United States Barack Obama.

Obama Sr. was born in Kanyadhiang village, Rachuonyo District on the shores of Lake Victoria just outside Kendu Bay, Kenya, at the time a colony of the British Empire, and raised in the village of Nyang’oma Kogelo, Siaya District.He was the son of Hussein Onyango Obama (c. 1895-1979) and his second wife, Akumu Habiba.

His family are members of the Luo ethnic group. Obama Sr. was born into a Muslim family, but was an atheist before he came to the United States.Before working as a cook for missionaries in Nairobi, Onyango had travelled widely, enlisting with the name Onyango Obama in the British colonial forces and visiting Europe, India, and Zanzibar, where he converted from Roman Catholicism to Islam. Onyango had at least three wives; Barack Obama Sr. was the son of Akumu, the second wife. However, he was raised by Onyango's third wife, Sarah, after Akumu left her family and separated from her husband in 1945. Obama Sr. was married in 1954 at the age of eighteen, in a tribal ceremony to Kezia, with whom he had four children.

At the age of 23, Obama Sr. enrolled at the University of Hawaii at Manoa, leaving behind a pregnant Kezia and their infant son. He had already turned away from Islam and become an atheist by the time he moved to the United States. On 2 February 1961, Obama Sr. married fellow student Ann Dunham in Maui, Hawaii.Obama Sr.'s and Dunham's son, Barack Obama II, was born on August 4, 1961. Dunham left school to care for the baby, while Obama Sr. completed his degree. He graduated from the University of Hawaii in June 1962, leaving shortly thereafter to travel to Cambridge, Massachusetts, where he would begin graduate study at Harvard University in the fall.

Later that summer, Dunham and the year-old baby Barack stopped to visit her friends in Mercer Island, Washington, the Seattle suburb where she had grown up, before joining Obama Sr. in Cambridge. However, mother and son soon returned to Seattle, where she enrolled at the University of Washington. Dunham, missing her family, then moved back to Hawaii and filed for divorce in Honolulu in January 1964. Obama Sr. did not contest, and the divorce was granted. He visited his son only once, in 1971, when Barack was 10 years old.