Ms. Ma. Esther O. Santos joined the PLDT-Smart Foundation (PSF) as President in 2011. She is an alumna of the University of the Philippines, Diliman where she took up her Masters degree in Development Economics as well as her BA in Economics. In 2013, Ms. Santos was also a member of the pioneer batch that completed the Advanced Management Program of the University of Asia & the Pacific and the IESE Business School in Barcelona, Spain.

She has also worked for financial institutions and a local conglomerate in various capacities as financial analyst, research head of equities and trust divisions, and fund manager. Before joining PSF, she was the only Filipino to be designated country delegate for Fundacion Codespa, a non-profit organization dedicated to international development cooperation that creates development strategies and programs, with His Royal Highness the Prince of Spain as honorary chairman. She also worked with several local foundations and advocacies for women and the youth. Her foundation experience mostly entailed strategic fund management, building strategy framework for implementation, and project management.

Ms. Santos is currently a member of the Board of Trustees of Radio Veritas and ASA Microfinance.