Mayan was born in Butuan City, Philippines and has lived in many different places in the Philippines. She graduated with a BS in Social Work from the University of the Philippines, Diliman; a Masters in Management at UP Mindanao and finished a short course in Strategic Perspective on Non-Profit Management (SPNM) at the Harvard Business School. In 2008, Mayan was awarded Social Entrepreneur of the Year by Ernst & Young and Schwab Foundation.
She co-founded the Migrant Forum in Asia and is a founding member of Migrant Rights International in Geneva. Villalba is a former board member for the Global Fund for Women in San Francisco. She also lectures on Social Entrepreneurship at Silliman University.
Working in Hong Kong and travelling to various parts of the world, Villalba was struck by how the Philippines is not able to develop like other countries post-independence, and by how many Filipinos worked in 3D (dangerous, dirty, difficult) jobs throughout the world. In 1996, she started Unlad Kabayan with the long-term goal for Filipinos to have decent jobs in their own country, so that overseas employment becomes a choice and not for lack of feasible options at home. She continues this work today as the executive director of Unlad Kabayan.