Mariano del Castillo

Mariano C. Del Castillo is an Associate Justice of the Supreme Court of the Philippines.

After graduating from San Beda College, Mariano del Castillo pursued law studies at the Ateneo de Manila University. He joined the Judiciary in 1989 as Municipal Trial Court Judge of San Mateo, Rizal before he was promoted to Regional Trial Court Judge of Angeles City in 1992, and later as Regional Trial Court Judge of Quezon City in 1995, where he was appointed First Vice-Executive Judge. He was appointed CA Justice in 2001. He was active in the Philippine Judges Association where he has served as its Director, Vice-President for Administration, Senior Vice-President, and Executive Vice-President.

Likewise, he has held various positions in religious, civic, community, and non-governmental organizations. He taught Practice Court II at the Ateneo College of Law and lectures at the Mandatory Continuing Legal Education (MCLE) and Philippine Judicial Academy (PHILJA) seminars. He was also a pre-Bar reviewer in Legal Ethics and was the Chair/Editor in Chief of the Court of Appeals Journal.

Justice Del Castillo has had a zero backlog in the CA since 2004. In 2005, he was conferred the Best Performing Court of Appeals Justice for 2004 and the Justice George A. Malcolm Award by the Rotary Club of Manila. In 2007, he was conferred the Presiding Justice Award for Outstanding Performance.

Del Castillo was accused of plagiarism in the opinion written for Isabelita Vinuya et al. v. Executive Secretary et al. The opinion allegedly misapplies the language and theories of an atricle written by Professor Evan Criddle (of Syracuse University College of Law) and Professor Evan Fox-Descent (of McGill University) which they wrote for the Yale Journal of International Law.