Arun Kumar Singh, born on 26 August 1961, is a retired Indian Administrative Service officer from the 1985 Bihar cadre. He holds a graduate degree in Mechanical Engineering. Over his career, he served in various capacities including District Collector and Magistrate, Divisional Commissioner, Joint Secretary, and Director. His past roles also include Secretary, Principal Secretary, Departmental Enquiry Commissioner, and General Secretary. Most recently, he was Commissioner in the Personnel and Administrative Reforms Department from 2 September 2019 to 27 February 2021. Singh’s extensive experience spans multiple administrative and leadership positions within the Bihar government.