Hermann Buhr Giliomee was born in Sterkstroom in the Eastern Cape on April 4, 1938. He went to school in Porterville and studied history at the University of Stellenbosch.

He subsequently worked for the Department of Foreign Affairs and lectured at the University of Stellenbosch. From 1983 to 1998 he was Professor in Political Studies at the University of Cape Town. From 1995 to 1997 he was president of the South African Institute of Race Relations. He is currently an extraordinary professor and research associate of the Department of History at the University of Stellenbosch.
Hermann Giliomee is the writer of various historical and political publications. In 2003 The Afrikaners – Biography of a People was published. It was also published in America and England. A year later Die Afrikaners: ’n Biografie was published. In 2008 he received the Helgaard Steyn Prize for Literature for Die Afrikaners. Nuwe geskiedenis van Suid-Afrika and New History of South Africa were published in 2007. It was co-written with the historian Bernard Mbenga.
In 1984 Hermann Giliomee was co-founder of Die Suid-Afrikaan, an Afrikaans magazine of opinions. In the 1980s he was a regular columnist for the Rand Daily Mail and the Cape Times.
He was an associate at Yale University in the USA (in the 1970s), Cambridge University (1982-1983), and the Woodrow Wilson Centre for International Scholars in Washington D.C. (1992-1993).