Born in Manila on 28 August, he hails from a family immersed in the field of law, starting with his great-grandfather, Marcelino R. De Santos, who obtained  a Bachiller en Leyes from the University of Santo Tomas in 1871, his grandfather, Dr. Isidoro O. De Santos, who was the representative of Manila in the 1st Philippine Legislature, and later his father, Alejandro F. De Santos, who was a product of the UP College of Law, 1940.

He has been a consistent honor student (having graduated Honorable Mention, St. John’s Academy, 1976; With Honors, UP Integrated School, 1980; Cum Laude, UP College of Social Science & Philosophy, 1984; and No. 27 in his batch, UP College of Law, 1988), while all throughout being an active student leader (President, Section 7-A, St. John’s Academy, 1976; President, UPIS Student Association, 1980; President, Association of Political Science Majors, 1984; President, UP Law Student Government, 1988).

His law practice has mainly been in Civil, Criminal, Corporate litigation (with Alampay & Manhit Law Offices [AMLaw]; Balgos & Perez Law Offices [BPLaw], and Villanueva, Gabionza & De Santos Law Offices [VGSLaw]), while simultaneously being the Managing Partner for his immediately preceding law firm for more than a decade, and maintaining his ties in the academe being a professorial lecturer mostly in remedial law subjects (Statutory Construction, Special Civil Actions, Injunctions, Special Proceedings, Evidence and Land Titles & Deeds) at the University of the Philippines College of Law, the Lyceum of the Philippines University College of Law, and the Ateneo Law School, as well as previously in the College of St. Benilde and the UP College of Business Administration (Partnerships & Corporation Law and Business Law).

Having founded the Firm, his main objective now is to make his forefathers proud, serve his clients to the best of his abilities, impart whatever he has learned through the years in terms of legal practice and office administration to his colleagues, and give back to the country in whatever way he can to contribute to its growth and development.