Justice Nagappan was administered oath by Odisha Governor M C Bhandare at a ceremony at the court premises here in the presence of a host of dignitaries.
Prior to his present assignment, Justice Nagappan was a senior judge of Madras High Court.
The post of Orissa high court Chief Justice was lying vacant since December when the then incumbent Justice V Gopala Gowda was elevated to the bench of the Supreme Court.
Senior judge of the High Court Justice Pradeep K. Mohanty was officiating as the acting Chief Justice of the State.