Chief Sunday Omoniyi Obiyinka, mni is the initiator cum Managing Director of Extension Publications Limited. He was born on 4th January, 1970. After his primary education, he attended Onireke Grammar School, Ibadan where he sat for his West African Senior School Certificate Examination (WASSCE) in 1987. Thereafter, he proceeded to University of Ilorin where he obtained Bachelor of Science degree in Chemistry/Education in 1992. 

His one year compulsory national youth service scheme took him to Delta State in 1993/94. In furtherance of his education, he was awarded Masters degree in Publishing and Copyright Studies by the University of Ibadan. He is a member of the National Institute for Policy and Strategic Studies (NIPSS), Kuru and a fellow of Chartered Institute of Local Government and Public Administration (FCPA).
He is currently a PhD student in Publishing and Copyright Studies at the University of Ibadan. His career as a publisher started when he took appointment with Onibonoje Publishers and Book Industries (Nig) Ltd; and served between 1996 and 2001.Sunday Obiyinka, having served in a publishing outfit, took interest in the industry which informed the establishment of Extension Publications Limited in 2004. The company has gained acceptability with outlets in all the geo- political zones of Nigeria and West Africa sub- region. As a leading voice in the Educational Publishing, both at home and abroad, Sunday Obiyinka holds membership of various professional bodies Nigerian Publishers Association (NPA), African Publishers Network (APNET), World Intellectual Property Organisation (WIPO), International Publishers Association (IPA), among many others. He is also an alumus of New York University and London School of Economics. Similarly, he is a member of the Institute of Directors (IoD).

In recognition of his immense contribution to both cultural and national values, he was conferred with the chieftaincy title of Jagun Agba-Oye of Ibadan by His Imperial Majesty, Oba Saliu Adetunji, Aje Ogungunniso 1, the recent past Olubadan of Ibadanland.
He is a regular participant at various bookfairs at the national and international levels, among which are London Bookfair, Ghana Bookfair, Frankfurt Bookfair, etc. Sunday Obiyinka’s flair for service and leadership has inspired him to birth other companies in the hospitality, printing, construction, and supplies industries. He is equally into export and import activities.Chief Sunday Omoniyi Obiyinka, mni’s hobbies include Travelling, Table Tennis and Networking. He is happily married and blessed with children.