Justice Oswald Leslie De Kretser II, CMG (7 June 1882 - 11 November 1959) was a Ceylonese (Sri Lankan) judge. He was a Puisne Justice of the Supreme Court of Ceylon. Born to Oswald Leslie De Kretser I a District Engineer of Public Works Department, Ceylon; he was educated at the Royal College, Colombo. In 1905 he became an Advocate of the Supreme Court of Ceylon and began his legal practice. He married Ruby Irene Leah Shirley Thomasz. One of his sons, Oswald Leslie De Kretser III also became a judge of the Supreme Court of Ceylon.