Tenneh was born in Blama, Kenema district, Eastern Province, Sierra Leone and was formerly a police officer with the Sierra Leone Police Force. She arrived in Australia on 21 October 2001 with an Offshore Humanitarian Visa 200 (refugee status). She has a Diploma in Community Welfare and a Bachelor of Community Welfare and International Social Development from the University of Western Sydney. She has trained and worked as a domestic violence project officer with SydWest Multicultural Services Inc. Tenneh has worked as a community development project officer for Immigration Women Speakout and Women at Risk and as a project worker for Liverpool Migrant Resource Centre. She has advocated for various refugee communities in Australia and is a member of the Sierra Leone Women Want Word of Australia. Tenneh is the co-founder of Transform DE People of Australia and Sierra Leone, Africa Sub-Sahara Relief and Development. She is the recipient of the 2011 award as one of most influential African Australian advocates for refugee women, both nationally and internationally. Tenneh won an award from the Australian Women’s Leadership award from the Australian Institute in 2016.
Tenneh is the first off-shore resettled refugee to deliver an NGO statement on behalf of NGOs at the UNHCR NGO Anual Consultations in 2006. In 2014 she delivered an NGO statement on international protection. Tenneh is currently working with asylum seekers and refugees at Settlement Services International and is the deputy chair for Women at Risk Working Group for Asia Pacific Refugee Rights Network (APRRN).