Ranasinghe Arachchige Nimal Gamini Amaratunga is a Puisne Justice of the Supreme Court of Sri Lanka.
Thereafter, Amaratunga attended University of Colombo obtaining a Bachelor of Laws Degree (LLB) in 1970.
Whilst still at the Attorney General's Department, in 1984, he obtained the Post Graduate Degree of Master of Laws (LLM) from the University of Colombo.
He has served as a High Court Judge in Ampara, Colombo, Badulla, Kegalle and Kurunegala.
He was made a Puisne Justice of the Supreme Court of Sri Lanka in January 2005.