Upon completing his PhD in 1982, Zeleza took up an appointment as a lecturer in the department of history at the University of the West Indies in Kingston, Jamaica, where he spent two years.

In August 1984, he relocated to Kenyatta University in Nairobi, Kenya, the country on which he had done his PhD dissertation and where he had spent a year between 1979–1980 conducting research.

In July 1990, he relocated to Trent University in Peterborough, Ontario, Canada, where he was appointed assistant professor in the department of history.

On 1 August 2009 he assumed his new role as Dean of the Bellarmine College of Liberal Arts at Loyola Marymount University in Los Angeles.

On 16 September 2015, Zeleza was appointed as the Vice-Chancellor of the United States International University Africa in Kenya with effect on 1 January 2016.

[6] The jury citation noted: The book is an exercise in historical reconstruction, and its strength and distinction above all lies in its bold and convincing challenge to hitherto accepted orthodoxies, terminologies, and interpretations, about the nature and development of African societies and economies.

In 2003, he was appointed by the United Nations Research Institute for Social Development (UNRISD) to a nine-member advisory board to oversee the publication of "Gender Equality: Striving for Justice in an Unequal World", a research study issued to mark the 10th anniversary of, and assess progress since, the United Nation's Fourth World Conference on Women, held in Beijing in September 1995.

Among the numerous conferences where he has given keynote addresses are those organised by UNESCO in Paris in December 2003 and the Association of African Universities in Cape Town in February 2005.

In Asia, he has also visited China and South Korea, and in Europe, he has been invited to France, Germany, Sweden, Norway, Italy, Britain, Switzerland, and the Netherlands, while in the Americas he has been to several Caribbean islands, Venezuela and Brazil.