Wijaya obtained his Bachaleor’s Degree in Agriculture at the University of Peradeniya, specialised in Agricultural Economics. He has a Master’s in Sociology from Texas A & M University and PhD in Rural Sociology from Penn State University, USA. He had a career as an Academic at the University of Peradeniya until the end of 2018. He was the Head of the Department of Agricultural Economics and Agricultural Extension, Dean of the Faculty of Agriculture, University of Peradeniya. Wijaya was the Secretary and Chair, Board of Study, Agricultural Extension of the Postgraduate Institute of Agriculture, Peradeniya. He was the Co-Chair of the UGC Standing Committee on Gender Equity and Equality. He worked as Senior Program Officer, Commonwealth Youth Program, Commonwealth Asia Centre, Chandigarh, India. He served as the Chief Executive Officer of the Sri Lanka Foundation Institute, Transparency International, Sri Lanka, and Facilitating Local Initiatives for Conflict Transformation (FLICT), GIZ and the South Asia Centre for Legal Studies. His research and teaching/training is in Sociology of Agriculture, Social Impact Assessment, Gender, Professionalism and Organisational Development, and Conflict Transformation.