Abdullah Hussain Haroon completed his education from Karachi Grammar School and later from the University of Karachi. He began his early career in public service as Election Coordinator for Pakistan Muslim League in 1970. Later he served as Councilor, Karachi Metropolitan Corporation (KMC) (1979–1985); Trustee Karachi Port Trust (KPT) (1980–1982); Member Provincial Assembly of Sindh (1985–1988), Speaker, Provincial Assembly of Sindh (1985–1986); and leader of opposition, Provincial Assembly of Sindh (1986–1988).

In August 2008, Mr. Hussain Haroon was appointed as the Permanent Representative of Pakistan to the United Nations and served as the Pakistan Ambassador to the United Nations from September 2008 to October 2012.

He was also given the portfolios of Ministry of Foreign Affairs, National Security Division, Ministry of Defence and Ministry of Defence Production to assist the Caretaker Prime Minister of Pakistan, Nasirul Mulk in managing the country till the 2018 Pakistani general election.

A scion of the Haroon family, Mr. Haroon is a businessman, social activist and has been a board member of various educational institutes, sports associations and charity organizations. He has served as Consultant, Pakistan Herald Publications Limited (PHPL) (1988–1989); delegate to the United Nations General Assembly; Member to the Board of Governors, Institute of Business Administration, Karachi (1996–1999); Director Board of Directors Karachi Electric Supply Corporation (KESC) (1997–1999); Chairman, Griffith College Karachi (1999–2005) and President, Pakistan-China Business Forum (1999–2004). Formerly, the president of English Speaking Union of Pakistan and he has also had the distinction of being the youngest president of the elite Sind Club in Karachi.