A proud product of the Philippine public school system (from basic to higher education), AGCC Manuel F. Santos Jr. obtained his Bachelor of Laws degree from the University of the Philippines (UP) in 2000. While in law school, he served as President of the Law Student Government, member of the Student Editorial Board of the Philippine Law Journal, Presiding Officer of the Paralegal Volunteers Organization and Student Volunteer at the UP Ugnayan ng Pahinungod Oblation Corps, the university's volunteer service program to serve the marginalized and underserved.

He likewise earned from UP his Bachelor of Arts (Political Science) degree, cum laude, in 1993 and a Diploma in Industrial Relations in 2004. In recognition of his academic achievements, he was inducted into the Honor Society of Phi Kappa Phi and the Pi Gamma Mu International Honor Society in the Social Sciences both in 1993.

After taking the 2000 Bar Exams, he commenced his legal career in the Supreme Court (SC) at the Office of Associate Justice Reynato S. Puno, who would later become Chief Justice in 2005. He began as Judicial Staff Officer V and was eventually promoted to Court Attorney VI, the highest court attorney position in the SC.

Three years later, in 2003, he transferred to the OGCC, where he started as Government Corporate Attorney and was assigned to the team which handles the agriculture, trade and tourism sectors. Aside from his regular functions consisting of litigation before lower and appellate courts and the SC; drafting legal opinions and contract reviews; and hearing or prosecuting administrative disciplinary cases, his previous important assignments in the OGCC included:

• Acting Corporate Secretary of Duty-Free Philippines Corporation, Tourism Promotions Board, Philippine Sugar Corporation and National Dairy Authority;
• Acting Chief, Legal Services Division of PHIVIDEC Industrial Authority;
• Composite Team member of the Department of Justice - Office for Competition (OFC), and as such, represented the country in several meetings of the ASEAN Experts’ Group on Competition (AEGC);
• Member of the OGCC Special Team that successfully represented a government corporation in an arbitration case administered by the International Court of Arbitration;
• Member of the OGCC PSALM Special Privatization Team, which handled the public bidding of Independent Power Producer (IPP) Administration Agreements; and
• Assisted in the dissolution proceedings of two government corporations attached to the Department of Agriculture and the liquidation of their assets.

He was appointed as AGCC in February 2025 and since then has been serving as team leader of the housing and retirement systems sectors team. At present, he is the Co-Chair of the Learning & Development Committee and member of the Performance Management Team. He was formerly Deputy Quality Management Representative for six years, starting in 2019, when OGCC first attained ISO 9001:2015 certification.

In his more than two decades of service in the Office, he has received several awards, including: Best Legal Opinion Drafter, Best Pleading Drafter, Most Significant and Major Case Award and Gantimpala Agad Award. Most importantly, he has received the Exemplary Behavior Award twice: in 2020 (on the occasion of OGCC's 85th Anniversary) and in 2023.

He is blissfully married to Ms. Gina Barretto-Santos, Vice-President and Learning Advisor at Citibank Regional Operating Headquarters (ROHQ). Gina is a multi-awarded and internationally-recognized Human Resources (HR) professional having received the "Global Top 100 Exemplary Coaching Leaders (Global Listing)” award for 2024 from the World HRD Congress and the "Top HR Icon" award from Advantage AI Inc. at its Philippines Leadership Awards 2025.