Hon Justice Monica Bolna'an Dongban-Mensem was born on 13th June, 1957, to the family of M.B. Douglas-Mensem; a retired Appeal Court Justice. She hails from Shendam Local Government Area of Plateau State. She obtained both her LL.B and LL.M degrees from the Ahmadu Bello University, Zaria.

She was a Visiting Lecturer on Press Law at the Catholic Media Centre, Kaduna from 1988–1992 and Part-time Lecturer at the University of Jos between 1989 and 1997.

From 1990–1993, Justice Dongban-Mensem served as Deputy Chief Registrar, Superior Courts and Protocol Affairs, and was appointed Judge, High Court of Justice, Plateau Judiciary from 1993–1996.

Hon Justice Dongban-Mensem transferred her service to the Federal Capital Territory (FCT) Judiciary in 1997, where she served until she was elevated to the Court of Appeal in 2003.

She was sworn-in as the President, Court of Appeal, on 19th June 2020, by the Chief Justice of Nigeria. Until her elevation, she was the Presiding Justice of the Court of Appeal, Enugu Division. Hon. Justice Dongban-Mensem is a Life Member of the Body of Benchers.