Gregory Santos Ong (born May 25, 1953) is a Filipino jurist and a former Justice of the Sandiganbayan. He was initially appointed as an Associate Justice of the Supreme Court of the Philippines by President Gloria Macapagal Arroyo on May 16, 2007, but his appointment was subsequently withdrawn after questions arose whether he met the constitutional requirement of natural-born citizenship. On September 23, 2014, he was found guilty of gross misconduct, dishonesty and impropriety and was subsequently dismissed from his position as Justice of the Sandiganbayan by the Supreme Court of the Philippines as a result of an investigation linking him to pork barrel scam mastermind Janet Lim-Napoles.