Dr Lee Tung Jean is currently First Deputy Secretary of the Ministry of Social and Family Development. Prior to this, she was the founding Chief Executive Officer of the Early Childhood Development Agency that was established on 1 Apr 2013. Dr Lee has also served in various government agencies such as the Ministry of Trade and Industry and the Ministry of Finance.

Dr Lee serves on the Boards of the National Council of Social Service, Casino Regulatory Authority, Agency for Integrated Care, and Singapore LNG Corporation Pte Ltd, amongst others. She was also a member of the Diversity Action Committee (2017-2018).