Professor Tennant is internationally known for his scholarly work on learning and education which focuses on promoting professional and personal formation and organizational and social change. His research has also engaged generally with issues and practices in post-school education being delivered in or by workplaces, educational institutions, professional and industry organisations, and community groups. He has 6 published books and over 50 journal articles and book chapters spread over a 30-year period. He has had visiting professorial appointments in universities around the world including Columbia University, University of Alaska, Syracuse University, Warwick University, Hokkaido University, and the University of British Columbia. He won the American Association of Adult Education's Cyril Houle Award for Literature in Adult Education for his book Psychology and Adult Learning.

In addition to his scholarly work Professor Tennant has held senior positions within the University of Technology, Sydney. He held substantive positions as Dean for over 13 years in the faculties of Education, Architecture Design and Building, and in the University Graduate Research School. He has also acted in the positions of Senior Deputy Vice-Chancellor and Deputy Vice-Chancellor (Research). At the University he has worked on policies, initiatives and planning in the areas of enhancing teaching quality, research development, professional consulting, enterprise bargaining, restructuring implementation, campus planning, contingency planning, course development, and international activities.

Outside the University Professor Tennant has undertaken quality assurance, course accreditation and review roles in his capacity as an Australian Universities Quality Agency Auditor, a Tertiary Education Quality and Standards Agency (TEQSA) expert, as a Specialist with the Hong Kong Council for the Accreditation of Academic and Vocational Qualifications, and as a Higher Education Assessor, Higher Education Directorate, NSW Department of Education and Training.