Hijab was born in Aleppo, Syria to Palestinian Arab parents, Wasfi Hijab and Abla Nashif, but grew up in neighboring Lebanon, where she earned a B.A. and M.A. in English Literature from the American University of Beirut. During her years of study in Beirut, Hijab worked as a journalist, but she left Lebanon in 1975 after the onset of the Lebanese Civil War. She traveled first to Qatar, and then to London, England, where she became the Editor-in-Chief of Middle East Magazine and appeared frequently in the media as a commentator on Middle East affairs.

She is prolific writer, having authored over 100 academic articles and two books (see below).

In 1989, Hijab moved to the United States, where she worked for ten years as a development specialist for the United Nations Development Programme in New York City. In 2000, she founded a consultancy firm, Development Analysis and Communications Services, which she still heads. As a consultant she has continued to work for UNDP; she has also done consulting work for World Bank, UNICEF, and Columbia University.

In 2006, she joined the Institute for Palestine Studies as a Washington, DC-based Senior Fellow. She remains an active media commentator, and has published opinion pieces in online journals, in addition to drafting policy notes on issues related to the Israeli-Palestinian conflict for the Institute for Palestine Studies.

Her commentaries and articles are syndicated by Agence Global