Alok Ranjan did his BA (honors) in Economics from St. Stephen's College, Delhi and MBA from Indian Institute of Management, Ahmadabad (IIM-A). He subsequently joined the IAS in 1978 after securing the fourth rank in the country. He was allotted to the UP (Uttar Pradesh) cadre. He served with distinction in various assignments in the State Government as well as Government of India before superannuating as Chief Secretary to the Government of UP in 2016. During his career he worked as District Magistrate, Municipal Commissioner, Secretary Basic Education, Secretary Finance, and Secretary to Chief Minister, Principal Secretary Technical Education, Urban development and environment to the State Government. He also held the post of Agriculture Production Commissioner and infrastructure and industrial development commissioner. In Government of India he held the assignments of Joint Secretary Defense and Managing Director NAFED.